The invention discloses a multichannel sound emission monitoring system and a positioning method in an underground engineering construction process. The system is characterized in that a plurality of three-dimensional sound emission sending devices are respectively connected with a multichannel sound emission synchronous data collection device, the multichannel sound emission synchronous data collection device is connected with an optical fiber network switch through a first photoelectric converter, and the optical fiber network switch is connected with an upper computer through a second photoelectric converter. By adopting the system provided by the invention, real-time monitoring, waveform display, real-time positioning, and signal strength and data recording of sound emission signals are completed, the underground engineering surrounding rock bodies are monitored in real time, the damage conditions of the rock bodies are reflected, water inrush premonition information can be discovered in time, and technical support is provided for water inrush disaster prevention.