Provided is a prism device applied to a periscope lens module. The prism device includes: a bearing frame; a supporting-restoring assembly; a prism; and shape memory alloy wires. The bearing frame includes a horizontal support plate, a vertical support plate, and two side plates. The shape memory alloy wires are connected to the supporting-restoring assembly and the bearing frame from the two side plates, respectively, so as to drive the supporting-restoring assembly to drive the prism to rotate about a first rotation center axis, and are connected to the supporting-restoring assembly and the bearing frame from the horizontal support plate and the vertical support plate, respectively, so as to drive the supporting-restoring assembly to drive the drive the prism to rotate about a second rotation center axis. The present invention replaces the electromagnetic driving with the shape memory alloy wire, thereby reducing a manufacturing cost.