Built-in high-strength steel door

The utility model relates to the technical field of ship steel door equipment, and discloses a built-in high-strength steel door which comprises a fixed door frame unit and a door body unit hinged in the fixed door frame unit, a trapezoidal table block is rotatably connected to the lower end of a threaded column, and when a steel door body is locked, the steel door body is locked by the trapezoidal table block. When a steel door body is locked, a rotating ring is rotated to enable a threaded column to drive a trapezoidal table block to move downwards, the inclined face of the trapezoidal table block makes contact with the inclined face of an inclined face contact block arranged in a connecting housing, the inclined face contact block abuts against the inclined face contact block to enable a column body to move and be inserted into a positioning inserting hole formed in the inner frame edge of a reinforcing frame body, and locking operation of the steel door body is completed. The operation is simple, the step