Compared with traditional superheterodyne transmitters, zero-IF transceiver is more suitable for communication system requiring high frequency spectrum utilization, because of its simple circuit structure, high integration, low power consumption and low cost. Aiming at the IQ imbalance of zero-IF receivers, a new pre-correction method for wideband transmitter is proposed and experimentally demonstrated to decrease the distortion caused by IQ imbalance. The new method of parameter rotation and autocorrelation of output signal is adopted to find the minimum amplitude of specific frequency point in the spectrum of received signal. Then, the corresponding compensation parameter is obtained. The experimental results show that the image rejection ratio (IRR) of test tone is improved by 50.5 dB. In addition, the EVM of QPSK is reduced to 20.72% compared with the uncorrected signals, and the 13.67 dB SNR improvement is obtained. These results reflect that without the training pilots, the new method shows the algorithm superiority for both narrowband signals and wideband sequences, which could highly improve the system performance.