The invention discloses an energy-saving and environment-friendly solar street lamp, which comprises a plurality of light pole units connected end to end. The light pole unit at the top is fixedly connected with a lamp head connecting seat, and the light pole unit at the bottom is detachably connected with the lamp holder. The upper surface of the base is equipped with a solar energy collection device, the lower surface of the lamp base connecting base is connected with a plurality of lamp base connecting arms and ultrasonic sensors, the lamp base connecting arm is equipped with an LED lamp head, and any lamp pole unit is equipped with a battery and a microcontroller. , the LED lamp holder, the solar energy collection device, and the storage battery are respectively electrically connected to the microcontroller. Compared with the prior art, the present invention adopts light sensors and ultrasonic sensors to adjust LED lighting, avoiding street lamps to keep running at full power all the time, and reducing waste of resources; multi-section light poles can be connected end to end in sequence, and can be flexibly installed, fixed or disassembled , high stability, through the use of light pole fasteners and light pole fixing tubes, the rapid installation and fixation of light poles can be realized, and the installation efficiency can be improved.