Abstract: It is of great practical significance to measure solar radiation in agricultural production, meteorology, and the environment. This paper mainly introduces a signal processing method of solar radiation measuring instrument suitable for the field environment. The radiation measuring instrument uses solar power to solve the problem of no mains electricity in the field environment and uses wireless communication to solve the problem of long communication distance between the upper and lower computers. Signal processing mainly includes signal modulation, signal amplification, bandpass filtering, and signal demodulation. Finally, the radiation measuring instrument is used to test the signal processing method, and the rationality of the signal processing method is proved by the measured data.