The invention relates to the field of deformation control on a retaining structure in a foundation pit excavation process, in particular to a parallel-connection double-mechanical-lock support head assembly of a support axial force servosystem for carrying out displacement control on a foundation pit retaining structure. The parallel-connection double-mechanical-lock support head assembly mainly solves the technical problem that the whole support head frame is necessarily dismounted when a jack of the existing support head is replaced after being damaged. The parallel-connection double-mechanical-lock support head assembly of the support axial force servosystem adopts the technical scheme that the parallel-connection double-mechanical-lock support head assembly comprises a support head frame. The parallel-connection double-mechanical-lock support head assembly is characterized in that the support head frame is internally provided with a jack body; trapezoidal threaded rods are arranged on the two sides of the jack body; lock nuts are arranged at the ends of the trapezoidal threaded rods; the ends of the trapezoidal threaded rods and the end of a jack piston are connected with threaded rod ball heads and a jack ball head respectively; and the threaded rod ball heads on the two sides are connected by a front reinforcing plate. The parallel-connection double-mechanical-lock support head assembly and the support axial force servosystem work jointly and can be applied in foundation pit engineering for controlling deformation of the foundation pit retaining structure, so that the safety of the foundation pit engineering is ensured.