An optical path switching method, wherein the method is applied to a surveillance module, the surveillance module comprises a camera, a teleconverter, a switching element, and a reflection element, wherein the camera includes a zoom lens to set the magnification of the camera, the teleconverter uses a fixed-focus lens and is of optical path folding structure, an emergent optical axis of the teleconverter is unparallel to an incident optical axis of the camera, an incident optical axis of the teleconverter is parallel to the incident optical axis of the camera, the switching element is configured to change a working status of the reflection element, and when the reflection element is in a first working state, the camera performs image capture alone, or when the reflection element is in a second working state, the reflection element is configured to reflect emergent light of the teleconverter to the camera along the incident optical axis of the camera, so that the camera and the teleconverter jointly perform image capture; wherein the reflection element comprises electrochromatic material glass, wherein the electrochromatic material glass switches between the first working state and the second working state based on whether it is energized, wherein, in the first working state, the electrochromatic material is transparent, directing light only through the camera, and wherein, in the second working state, the electrochromatic material is in a reflection mirror state, directing light through the camera and the teleconverter, wherein and the method comprises: determining, by a determining module of the surveillance module, a target magnification; and when the target magnification is less than or equal to a maximum magnification of the camera, setting a magnification of the camera to the target magnification; and setting (S 162), by a control module of the surveillance module, the reflection element to be in the first working state, and performing image capture by using the camera; or when the target magnification is greater than a maximum magnification of the camera, setting, by the control module of the surveillance module, a magnification of the camera to a first magnification, wherein a product of the first magnification and a magnification of the teleconverter is the target magnification, and the target magnification is not greater than a product of the maximum magnification of the camera and the first magnification; and setting, by the control module of the surveillance module, the reflection element to be in the second working state, and performing image capture by using both the camera and the teleconverter. wherein the reflection element comprises electrochromatic material glass, wherein the electrochromatic material glass switches between the first working state and the second working state based on whether it is energized, wherein, in the first working state, the electrochromatic material is transparent, directing light only through the camera, and wherein, in the second working state, the electrochromatic material is in a reflection mirror state, directing light through the camera and the teleconverter, wherein and the method comprises: determining, by a determining module of the surveillance module, a target magnification; and when the target magnification is less than or equal to a maximum magnification of the camera, setting a magnification of the camera to the target magnification; and setting (S 162), by a control module of the surveillance module, the reflection element to be in the first working state, and performing image capture by using the camera; or when the target magnification is greater than a maximum magnification of the camera, setting, by the control module of the surveillance module, a magnification of the camera to a first magnification, wherein a product of the first magnification and a magnification of the teleconverter is the target magnification, and the target magnification is not greater than a product of the maximum magnification of the camera and the first magnification; and setting, by the control module of the surveillance module, the reflection element to be in the second working state, and performing image capture by using both the camera and the teleconverter. determining, by a determining module of the surveillance module, a target magnification; and when the target magnification is less than or equal to a maximum magnification of the camera, setting a magnification of the camera to the target magnification; and setting (S 162), by a control module of the surveillance module, the reflection element to be in the first working state, and performing image capture by using the camera; or when the target magnification is greater than a maximum magnification of the camera, setting, by the control module of the surveillance module, a magnification of the camera to a first magnification, wherein a product of the first magnification and a magnification of the teleconverter is the target magnification, and the target magnification is not greater than a product of the maximum magnification of the camera and the first magnification; and setting, by the control module of the surveillance module, the reflection element to be in the second working state, and performing image capture by using both the camera and the teleconverter.