The invention relates to a field assembly type optical fiber connector. The end of a neck insert core is connected with a dark fiber and inserted into the head of a box shell after cementing, a plastic bolt is pressed in to fix the neck insert core with the box shell, a V-shaped slot aluminum sheet is arranged inside the box shell, a wire block is arranged at the tail of the box shell which is fixed with the wire block through a plastic bolt, a metal collet is sleeved on the box shell, a spring is sleeved on the head of the wire block, a spring seat is sleeved at the tail of the wire block and contacts with the spring, a wire fixing slot is inserted into the spring seat and contacts with the wire block, an inner shell is covered on the peripheries of the neck insert core, the box shell and the spring seat, a square cover is clamped into the spring seat so as to fix the skin of the optical fiber, a key is placed into the end of the inner shell, a dustproof cap is sleeved on the neck insert core tightly so as to protect the neck insert core, and the head of the inner shell is sleeved into a short shell. The connector is resistant to high and low temperatures, good in repeatability, high in crush resistance and tensile property, compact in structure, provided with an interlock structure and high in reliability.