This paper proposes an efficient channel mismatch correction method for TIADC (timeinterleaved analogtodigital converter) system, in order to overcome the complexity and inefficiency of the conventional correction method. Based on the principle of equivalent sampling, the sampling data of a certain number of cycles is overlapped to one cycle highresolution data, from which all parameters needed to correct channel mismatch, such as average value, amplitude range and phase, can be acquired. According to these parameters, the proposed method can correct offset error, gain error and time skew directly, so avoid the great calculation of FFT or curve fitting. Simulation and application results show that the method can measure abovementioned errors rightly and enhance the performance of TIADC efficiently, at the same time, reduces the complexity and calculation.