通过调整相控阵超声检测仪阵元数、起始阵元和末阵元的方式，组成不同阵元数的虚拟探头，利用RB-1型超声检测标准试块，在框住H（工件厚度）=25 mm的底面回波条件下，进行了两组试验，首先测量了探头各单独阵元在底面回波达到满屏高度80%时的增益值，分析了单阵元激发声压的波动性；然后调整参数设置，测量记录了不同阵元数虚拟探头的底面回波达到满屏高度80%时的增益值，并计算了相同阵元数情况下，所有虚拟探头的增益均值和方差均值，得出虚拟探头增益均值和方差均值随其阵元数量的变化趋势。基于试验数据分析了探头阵元声压稳定性和虚拟探头声压对实际检测的影响，为相控阵超声检测的实际应用提供了一些参考。

By adjusting the number of elements, starting elements, and ending elements of the phased array ultrasonic testing instrument, virtual probes with different number of elements were formed. Two sets of experiments were conducted using RB-1 type ultrasonic testing standard test blocks under the condition of bottom echo of H=25 mm. Firstly, the gain values of each individual element of the probe were measured when the bottom echo reached 80% of the full screen height, and the fluctuation of excitation sound pressure of a single element was analyzed; Then the parameter settings were adjusted, the gain value was measured and recorded when the bottom echo of virtual probes with different array elements reaches 80% of the full screen height, the gain mean and variance mean of all virtual probes with the same array elements were calculated, and the change trend of the gain mean and variance mean of virtual probes with their array elements was obtained. Based on experimental data, the stability of probe array element sound pressure and the impact of virtual probe sound pressure on actual detection were analyzed, providing some reference for the practical application of phased array ultrasonic testing.