The present invention relates to an interlocking bone fastener, which comprises a bone plate body. The bone plate body comprises at least one fixing hole. The fixing hole has an interior that has a first inside wall and a second inside wall. The first inside wall has a surface on which a first internal thread is formed. The second inside wall has a surface on which a second internal thread is formed. The number of the first internal thread is less than that of the second internal thread. The first inside wall is extended upward to form a sidewall. The sidewall has an inside surface in which a third internal thread is formed. With the sidewall, the fixing force of the interlocking bone fastener is increased and high security is achieved. Further, the bone plate body, which is relatively thin, is thus in possession of high conformableness and movability.本發明係關於一種互鎖式骨固定器，其係包含一骨板本體，該骨板本體上具有至少一固定孔，該固定孔之內側具有一第一內側壁及一第二內側壁，該第一內側壁之表面具有一第一內螺牙，該第二內側壁之表面具有一第二內螺牙，該第一內螺牙之數量少於於該第二內螺牙，其中該第一內側壁進一步向上沿伸設有一側壁，該側壁之內側設有一第三內螺牙，透過該側壁以提升互鎖式骨固定器之鎖固力，具有高安全性，並使較薄之該骨板本體具有高舒適性與活動性。
