The near-surface detection capability is improved by analyzing the crosstalk mechanism and crosstalk isolation method between ultrasonic phased array probe elements. The influences of ultrasonic crosstalk between the elements before and after installing the wedge on the testing signal and testing sound field are analyzed based on the numerical simulation model. Then the capability of the probe wedge on isolation of the crosstalk of array element and near-surface testing signal is analyzed. The wedge block optimization scheme is proposed, and verified by the experimental method. The results indicate that the numerical model can visually display the ultrasonic crosstalk between the array elements, and the proposed wedge block optimization scheme can isolate the crosstalk signal between the array elements in the time domain and the near-surface detection signal from each other. The phased array probe after optimizing the wedge can perform imaging testing on flat-bottomed holes with a depth of 2 mm and a diameter of 0. 3 mm, the near-surface detection capability is significantly improved.