Underwater concrete pouring system and construction method

The invention relates to an underwater concrete pouring system and a construction method.The underwater concrete pouring system comprises fiber bragg grating demodulation equipment, take-up and pay-off winding equipment, a transmission optical fiber, a guide pipe and fiber bragg grating pressure-temperature sensors, and the fiber bragg grating pressure-temperature sensors are distributed and fixed to the tail end of the guide pipe in an array mode through sensor bases; the fiber bragg grating pressure-temperature sensors are connected in series in a welding manner, the fiber bragg grating pressure-temperature sensors are connected with the fiber bragg grating demodulation equipment through transmission optical fibers, and the transmission optical fibers are fixed on the side wall of the conduit through fixing buckles; the upper end of the guide pipe is connected with the take-up and pay-off According to the invention, automatic monitoring of the liquid level change of pile foundation (diaphragm wall) pouring