LED street lamp constant current control power supply

The invention discloses an LED street lamp constant current control power supply which belongs to a power supply circuit. A surge and peak voltage resistant circuit is connected with commercial power and then is connected with an EMC (Electro Magnetic Compatibility) filtering circuit, a full bridge rectification circuit, a PFC (Power Factor Correction) circuit and a voltage reducing and stabilizing circuit in sequence, wherein one end of the voltage reducing and stabilizing circuit is used for outputting, while the other end is connected with the an expanded-current constant-current circuit and a freewheel diode; the freewheel diode is connected with an energy storage inductance and then is output, moreover, the freewheel diode is also connected with the expanded-current constant-current circuit which is connected to a PWM (Pulse-Width Modulation) output circuit and a peak detection circuit; the PWM output circuit takes a main control chip U1 as a core, an DRV end is connected with the expanded-current constant-current circuit, a VDD end is connected with the voltage reducing and stabilizing circuit, a CS end is connected with a peak collecting circuit and an EN is connected with a photosensitive dimming circuit. The LED street lamp constant current control power supply has stable and reliable output, can be used in series connection as groups, and also has photosensitive dimming function for adjusting the brightness of a street lamp according to the illumination condition of the environment, thereby saving energy and prolonging service life very well.