A multipath current source switching device, comprising a switching control unit; a number N of current paths each composed of a constant current source circuit and a switching circuit; a plurality of loads, the number of the loads being the same as that of the current paths, wherein, one terminal of a first load of the plurality of loads is coupled to a load power supply, and the other terminal thereof is coupled to an output terminal of the constant current source circuit of the first current path and to one terminal of a second load of the plurality of loads; one terminal of an i th load is coupled to the other terminal of an (i-1) th load of the plurality of loads and the other terminal of the i th load is coupled to an output terminal of the constant current source circuit of the i th current path; each constant current source circuit is coupled to the switching control unit via its respective switching circuit and is adapted to output a current according to an operating voltage provided by the switching circuit; and under a control of the switching control unit, in switching between a first current path of said N current paths to a second current path of said N current paths, an operating voltage output by the switching circuit of the first current path to be switched off is adapted to be decreased according to a predetermined voltage variation quantity until the operating voltage is zero, and simultaneously, an operating voltage output by the switching circuit of the second current path to be switched on is adapted to be increased to the highest operating voltage according to the predetermined voltage variation quantity, such that the current in any one of the loads does not exceed a predetermined current during said circuit switching; wherein the number N is an integer not less than 2, and i=2, 3, 4,..., N, characterized in that each switching circuit comprises: a counter (201, 204, 207), configured to perform a subtract counting according to a clock signal from the switching control unit when receiving a high level control signal from the switching control unit, perform an add counting according to the clock signal from the switching control unit when receiving a low level control signal from the switching control unit, and output a counting signal; and a digital-to-analog converter (202, 205, 208), configured to generate the corresponding operating voltage output according to the counting signal from the counter (201, 204, 207) to control an output of the corresponding constant current source circuit. a counter (201, 204, 207), configured to perform a subtract counting according to a clock signal from the switching control unit when receiving a high level control signal from the switching control unit, perform an add counting according to the clock signal from the switching control unit when receiving a low level control signal from the switching control unit, and output a counting signal; and a digital-to-analog converter (202, 205, 208), configured to generate the corresponding operating voltage output according to the counting signal from the counter (201, 204, 207) to control an output of the corresponding constant current source circuit.