A needle protecting module of an injection device in connecting with a syringe (2) has a needle base (22), a needle body (23), a tube module (3), a mounting tube (4), an elastic unit (5), and a stopping unit (6). The syringe (2) has a tube body (20) and an axis. The needle body (23) transfixes the needle base (22) and communicates with the tube body (20) for medication injection. The needle base (22) is removably engaged with the tube body (20) and bearing the needle protecting module is transfixed by the needle body (23). The tube module (3) is mounted around the needle base (22) and has an annular space (30). The mounting tube (4) is movably inserted into the annular space (30). The elastic unit (5) is mounted in the annular space (30) and abuts both the mounting tube (4) and the needle base (22) bilaterally. The stopping unit (6) is moveably mounted in the annular space (30) and is selectively engaged with the mounting tube (4).
