The invention relates to a shifting fork shaft with an interlocking structure. The shifting fork shaft comprises a first and second gear shifting fork shaft part, a fifth reverse gear shifting fork shaft part, a reverse gear shifting fork, a fifth gear shifting fork, a fifth reverse gear shifting fork clamp ring, a locking pin and a return spring, wherein a first and second gear locking pin limitation groove is formed in the first and second gear shifting fork shaft part; a fifth reverse gear locking pin limitation groove is formed in the fifth reverse gear shifting fork shaft part; a fifth reverse gear clamp ring groove is formed in the fifth reverse gear shifting fork shaft part; and the fifth reverse gear shifting fork clamp ring is clamped into the fifth reverse gear clamp ring groove. Through the structure of the locking pin, the first and second gear locking pin limitation groove and the fifth reverse gear locking pin limitation groove, normal operation of gear shifting is ensured by action of the locking pin in a fifth gear or reverse gear shifting process; through the action of the return spring, a force required by return is little; and interlocking between the first and second gear shifting fork shaft part and the fifth reverse gear shifting fork shaft part is realized in a neutral gear.