Abstract: Abstract: The power supply of the sensors driving circuit inside the solar greenhouse was restricted by the wired power supply, it is necessary to modularize and simplify the installation of the sensor and the design of the power supply. The wireless transmission and microwave transmission technologies were used as the power supply for the sensor drive circuit in the greenhouse in this paper. Based on the built-in photovoltaic microwave wireless power transmission system, the influence of various environmental factors on the transmission efficiency during the transmission process from the transmitting end to the receiving end was explored. The electromagnetic radiation of the transmitting antenna was simulated by using Ansoft HFSS software, and the radiation range of the transmitting antenna was obtained. On basis of energy conservation law and microwave theory, the relationship between received power and radiation efficiency, receiving distance and antenna size under the conditions of ideal environment and illumination intensity was analyzed by using MATLAB software. Taking the electromagnetic wave environment in the greenhouse at different distances and different time periods in one day of December in Harbin's winter as the test object, the influence of the electromagnetic wave environment on the receiving power of photovoltaic microwave wireless power transmission system was tested and analyzed. The method of improving the transmission efficiency of solar greenhouse wireless transmission system was further explored. The structure of microstrip antenna array was given and the design concept of RC varactor diode automatic phase modulation circuit was proposed, and the reason why the RC varactor automatic phase modulator was used to make the phase of each array element in phase was deduced theoretically. Based on this theory and research, the microstrip antenna array was simulated and analyzed subsequently. Aiming at the design problem of microwave emission source, a design scheme of microwave power source with low power loss was proposed. The theoretical circuit diagram was given and simulated. The effect that microstrip antenna array can improve and enhance wireless transmission efficiency in solar greenhouse had been verified by further experiments. The test results showed that the system can effectively supply power for the sensor equipment within 8 m when the transmitting power was 500 W by microwave wireless transmission method and it can get 19.28 dB antenna gain of the maximum radiation direction of the microstrip antenna with 6×7 structure. Compared with the horn antenna, the gain of the microstrip antenna array is improved, that is, the orientation of the microstrip antenna array is better. The transmission efficiency can be improved by using the microstrip antenna array method, and the average receiving power can be increased by 1.58 W in the range of 0 ~8 m.