In order to further analyze and optimize the performance of capacitive ultrasonic transducer (CMUT), the equivalent circuit models of CMUT cell and CMUT array were established, and the equivalent circuit simulation was carried out. First, CMUT small signal equivalent circuit model was deduced, and then the circuit simulation software Advanced Design System (ADS) was used to establish CMUT cell equivalent circuit for the calculation. The influence of different amplitudes and periods of AC voltage on the emission characteristics of CMUT cell was analyzed. The results show that the larger the amplitude and duration of AC voltage, the larger the vibration displacement and output sound pressure of the CMUT cell, and the better the emission performance. In addition, the equivalent circuit model of CMUT array was derived based on the mutual radiation impedance, and the frequency characteristics of CMUT array with different cell sizes, spacing and numbers were analyzed by ADS simulation. The results show that the size, spacing and number of cells all affect the frequency of CMUT array. The above analysis results provide theoretical reference for the design and testing of CMUT.