The invention relates to a mine cage positioning system based on fiber bragg grating strapdown inertial navigation and a method and belongs to the field of coal mine security detection. The mine cage positioning system comprises three parts, namely, a ground data processing and control subsystem, a shaft data transmission communication subsystem and an inertial navigation system, wherein an inertial unit is used for measuring accelerated velocity and angular velocity of cage motion; an inertial system is used for resolving and acquiring the accelerated velocity and angular velocity information of the cage; a radio frequency antenna network is used for uploading the data to a ground data processing system; and a ground processing system is used for processing the inertial unit information, thereby acquiring the real-time position and posture information of the cage. The system utilizes a fiber bragg grating inertia sensing technique, has the advantages of high anti-interference capacity, high reliability, high measurement precision, high instantaneity and small error and is not influenced by well depth, air condition in the well, sliding of hoisting rope, elastic elongation, wriggling, and the like.