The invention relates to a high-efficiency LED 
constant current driving circuit. The circuit comprises an input rectification filter circuit, a switch power 
supply management chip, an isolation switch 
transformer, a primary clamping circuit of the 
transformer, an output rectification filter circuit, an output current sampling circuit, a reference 
voltage generation circuit, a comparison circuit and a photoelectrical 
coupling circuit, wherein the input end of the input rectification filter circuit is connected with commercial AC 
electricity, while the output end is connected with a primary winding of the isolation switch 
transformer through the switch power 
supply management chip; the primary clamping circuit of the transformer is connected in parallel with the primary winding of the isolation switch transformer; the input end of the output rectification filter circuit is connected with the primary winding of the isolation switch transformer, while the output end is connected with LED load; an output current sampling circuit is connected in series with the LED load; the input end of the reference 
voltage generation circuit is connected with the LED load; and the input end of the comparison circuit is connected with the output current sampling circuit and the reference 
voltage generation circuit, while the output end is connected with the switch power 
supply management chip through the photoelectrical 
coupling circuit. The circuit improves the circuit integration degree, the reliability, the 
constant current precision and the circuit conversion efficiency.