The experiment focuses on the design of constant current driver of Light Emitting Diode (LED) circuit with hysteresis and over-temperature buffer protection, which consists of four modules a constant current driver module，an over-temperature shutdown module，a delay reset module and an over-temperature hysteresis buffer module. The design has realized the function of double temperature hysteresis and thermal buffer protection. The time-domain and temperature range are adjustable in this stage of buffer. The circuit has a temperature hysteresis interval of 5 ℃ and 29 ℃ in the thermal buffer jump points and thermal breakpoint respectively, which avoids the thermal oscillation in circuit. This design expands the span of the normal work area of the circuit，ensuring a stable and efficient operation of the circuit.