The invention provides a turning returning locking mechanism assembly. The turning returning locking mechanism assembly comprises an unlocking oil cylinder, an unlocking spring, a returning spring, a mechanical lock assembly, a rotating hinge pin, a returning cylinder, a telescoping cylinder, a telescoping shaft, a left supporting seat fixing nut, a left spring supporting seat assembly, a right spring supporting seat assembly, an inter-cylinder check ring, a hinge pin, an unlocking spring supporting seat, an upper unlocking cylinder support, a lower unlocking cylinder support, a ball stud, a locking sensor and an unlocking sensor. According to the turning returning locking mechanism assembly, a brand new turning returning locking mechanism assembly is developed and can be telescoped by following a rear axle turning hydraulic cylinder while a rear axle normally turns; in case that the rear axle is not returned, the mechanical holding and rigid locking of a rear axle turning rod system in an intermediate position can be kept; in case of electrical or hydraulic fault of a whole-wheel turning system, passive active returning is performed and rigid locking is realized, so that the reliability of the whole whole-wheel turning device set is greatly improved.