A horizontal five-axis turning plate type machining center includes a support base, a lathe bed arranged on the support base and a column arranged on the support base, wherein the lathe bed and the column are fixedly connected through a connecting arm, a turning plate device is arranged on the support base, an X-direction sliding plate capable of sliding in an X direction on the lathe bed is arranged on a side, facing the column, of the lathe bed, and a third driving unit capable of driving a workbench to perform position conversion between a turning plate and the X-direction sliding plate is arranged on the turning plate.