Aiming at the problem of weak light signal detection and temperature influence in compleX environments, a design scheme with MSP430 as the core controller, avalanche diode（APD）as the sensor and long rang radia（LoRa）technology as the data transmission is proposed. This circuit uses a bias adaptive temperature compensation circuit to make the bias voltage change with temperature, so as to stabilize the APD gain. The eXperiments show that the APD boosting is less affe cted by the tempera-ture compensation circuit and the gain is stable at 100 ±5 dB. At the same time, the scheme detects the weak light signal with an error of less than 3.92% and can remotely monitor the weak light intensity change in real time within 10 km of a plant area.