The invention relates to a detection system and device for microwave solid flow. The system comprises a Doppler echo collection module, a sensing plate, a conversion plate and an upper computer. The system is characterized in that the sensing plate comprises an A/D (analog-digital) conversion module, a filter downsampling module and an FPGA signal processing system; the conversion plate is used for converting digital signals into current signals, and the current is output and used as a signal source of a display device. By adopting the detection method, signals of a microwave solid flow meterare processed, the functions of all the modules are integrally designed, the signals are subjected to smoothing and constant false alarm processing through the FPGA multiple times, the defects of a traditional flow meter are overcome, accurate measurement and monitoring of flow information are achieved, the sensitivity is high, the anti-interference capacity is high, the device is easy to control,and free falling, dilute phase conveying and concentrated phase conveying can be monitored in real time.