Abstract: To meet the requirements of sonar equipment testing and underwater target echo simulation, a sonar measurement and control system for underwater target simulation has been designed and implemented. The system adopts a modular architecture. Its hardware centers on a Field-Programmable Gate Array (FPGA), a gain-adjustable power amplifier circuit, and an acoustic transducer—enabling the generation and controllable emission of multiple types of underwater target echoes, including both artificially generated signals and experimentally measured signals. The software is developed on the Qt platform and provides functions such as real-time parameter calculation, configuration management, data storage, and visualization. It supports flexible construction and output of acoustic emission signals with user-defined simulated distances, signal intensities, and arbitrary waveforms. Experimental results show that the output signal gain dynamic range exceeds 50 dB; the output sound pressure level exhibits a good linear relationship with gain variation; and the measured sound pressure level error remains within ±1 dB. The system reliably simulates multiple types of target echoes and ambient noise. It operates stably under continuous operation, and its parameter control accuracy meets the design specifications. The system is applicable to sonar equipment performance testing, underwater target echo simulation, and related underwater acoustic experiments and engineering research.