A threshold correction method for a multi-voltage threshold sampling digitization device, comprising: generating a triangular wave, and measuring the slope k1 of the rising edge part and the slope k2 of the falling edge part of the waveform of the triangular wave and the peak value amplitude Vpeak thereof, the width DOT of the part of the pulse higher than an actual working threshold Vt being represented as DOT(Vt) = (Vpeak - Vt)/k1 - (Vpeak - Vt)/k2 setting n groups of threshold pairs calculating a threshold under an actual working state using the measured pulse width DOT according to a formula and establishing a threshold correction function according to a corresponding relationship between actual working state thresholds and reference voltages set practically, and then correcting a set threshold according to the function. The method can effectively solve the problem of decreasing sampling precision caused by a comparator due to inconsistency of a set reference voltage set practically and an actual working state threshold under an actual working state. By applying this method, the use of a high-precision comparator can be omitted in an MVT device, thereby effectively reducing the cost of the MVT device.