To provide accurate and reliable data for underground mine water inrush accidents and achieve real-time continuous monitoring of rock stress,seepage water temperature,and water pressure in submarine mines,a multifunctional monitoring instrument for rock stress,water pressure,and water temperature was developed.The technical goals and working principles of the instrument are described,and the data storage and transmission mechanisms are analyzed.The practical application in the submarine mining field of Sanshandao gold mine shows that the maximum water pressure error of the instrument is 0.1 MPa,and the temperature error is 0.3 ℃,which meets the engineering requirements and enables real-time continuous monitoring of underground mining areas,rock stress,water pressure,and water temperature with reliable data.