The invention provides a multi-ADC high-speed crossing sampling calibration device and method, and the method comprises the steps: phase calibration, gain calibration and offset calibration. The phase calibration mainly solves a delay consistency problem of sampling clocks, the gain calibration mainly solves an amplitude consistency of four signals and the offset calibration mainly solves an offset consistency problem of four signals. Through the calibration of the phase, gain and offset of four-way ADCs with the 2.5 GSa / s sampling rate, the device and method enable the sampling rate of the four ADCs to reach 10 GSa / s during crossing sampling. Moreover, the waveform does not have distortion after data recombination, and the performance indexes meet the ideal requirements. A whole testing calibration control circuit is implemented through upper computer software and an FPGA. After calibration, the phase, gain and offset are guaranteed to be consistent, and a calibration result is complemented during collection display, thereby enabling the phase difference of four collection clocks to be 100ps, and enabling the gain and offset to be equal.