In order to realize the synchronous collection of loose particle signals generated inside sealed electronic equipment, a synchronous acquisition system for loose particle signal based on Pulse Per Second(PPS) is designed. Aiming at the problem of poor consistency in the synchronous acquisition of multi-channel loose particle signals, a dual Microcontroller Unit(MCU) control and memory sharing structure is adopted to realize the separation of data reading and data writing during the signal collection process. The external interrupt is triggered by Beidou PPS, and the synchronous collection of the signals in each channel is realized. By setting the Universal Time Coordinated(UCT) as the label of the multi-channel signal collected in a single pulse, the resynchronization of the transmission signal is realized. The test shows that the synchronization error of signal collection in each channel is at the magnitude of microsecond, and the time label of the signal is correct, which provides an important reference for the detection of loose particle signals.