A driving circuit for driving a light emitting diode, LED, load, the driving circuit comprising: the LED load; a power transistor (Qs) connected in series with the LED load and configured to receive an input voltage (VBUS) varying periodically; and a control circuit, characterized in that, the control circuit is configured to: obtain a voltage between two ends of the LED load, the voltage between two ends of the LED load being a driving voltage (VLED) for the LED load; obtain the input voltage (VBUS); and calculate a difference between the input voltage (VBUS) and the driving voltage (VLED) for the LED load; in a time period in which the input voltage (VBUS) is higher than the driving voltage (VLED) for the LED load, control the power transistor (Qs) to operate in a linear mode; and in the time period, control a change of an instantaneous current flowing through the power transistor (Qs) based on a difference between the input voltage (VBUS) and the driving voltage (VLED) for the LED load by an open-loop control, without calculating an error between an average current flowing through the LED load and a desired current, to cause the average current flowing through the LED load to meet a predetermined requirement for driving the LED load to emit a light having a desired brightness; wherein controlling the change of the instantaneous current flowing through the power transistor (Qs) based on the difference between the input voltage (VBUS) and the driving voltage (VLED) for the LED load by the open-loop control comprises: when the difference between the input voltage (VBUS) and the driving voltage (VLED) for the LED load is a first difference, controlling the instantaneous current flowing through the power transistor (Qs) to be a first current; and when the difference between the input voltage (VBUS) and the driving voltage (VLED) for the LED load is a second difference, controlling the instantaneous current flowing through the power transistor (Qs) to be a second current, wherein the first difference is less than the second difference, and the first current is greater than the second current. the LED load; a power transistor (Qs) connected in series with the LED load and configured to receive an input voltage (VBUS) varying periodically; and a control circuit, characterized in that, the control circuit is configured to: obtain a voltage between two ends of the LED load, the voltage between two ends of the LED load being a driving voltage (VLED) for the LED load; obtain the input voltage (VBUS); and calculate a difference between the input voltage (VBUS) and the driving voltage (VLED) for the LED load; in a time period in which the input voltage (VBUS) is higher than the driving voltage (VLED) for the LED load, control the power transistor (Qs) to operate in a linear mode; and in the time period, control a change of an instantaneous current flowing through the power transistor (Qs) based on a difference between the input voltage (VBUS) and the driving voltage (VLED) for the LED load by an open-loop control, without calculating an error between an average current flowing through the LED load and a desired current, to cause the average current flowing through the LED load to meet a predetermined requirement for driving the LED load to emit a light having a desired brightness; obtain a voltage between two ends of the LED load, the voltage between two ends of the LED load being a driving voltage (VLED) for the LED load; obtain the input voltage (VBUS); and calculate a difference between the input voltage (VBUS) and the driving voltage (VLED) for the LED load; in a time period in which the input voltage (VBUS) is higher than the driving voltage (VLED) for the LED load, control the power transistor (Qs) to operate in a linear mode; and in the time period, control a change of an instantaneous current flowing through the power transistor (Qs) based on a difference between the input voltage (VBUS) and the driving voltage (VLED) for the LED load by an open-loop control, without calculating an error between an average current flowing through the LED load and a desired current, to cause the average current flowing through the LED load to meet a predetermined requirement for driving the LED load to emit a light having a desired brightness; wherein controlling the change of the instantaneous current flowing through the power transistor (Qs) based on the difference between the input voltage (VBUS) and the driving voltage (VLED) for the LED load by the open-loop control comprises: when the difference between the input voltage (VBUS) and the driving voltage (VLED) for the LED load is a first difference, controlling the instantaneous current flowing through the power transistor (Qs) to be a first current; and when the difference between the input voltage (VBUS) and the driving voltage (VLED) for the LED load is a second difference, controlling the instantaneous current flowing through the power transistor (Qs) to be a second current, wherein the first difference is less than the second difference, and the first current is greater than the second current. when the difference between the input voltage (VBUS) and the driving voltage (VLED) for the LED load is a first difference, controlling the instantaneous current flowing through the power transistor (Qs) to be a first current; and when the difference between the input voltage (VBUS) and the driving voltage (VLED) for the LED load is a second difference, controlling the instantaneous current flowing through the power transistor (Qs) to be a second current, wherein the first difference is less than the second difference, and the first current is greater than the second current.