A linear drive device includes: a motor; a speed-reducing transmission stage having: a pinion gear fixedly connected to an output shaft of the motor, and a transmission gear meshing with the pinion gear; a linear transmission stage configured to transform a rotational movement of the transmission gear into a linear movement of an output connecting rod, the output connecting rod being received in a sleeve member so as to only move linearly; a spiral trench arranged on the transmission gear; and a follower received in the spiral trench so as to be movable in the spiral trench. The follower is connected to the output connecting rod via a connector, and the connector is configured as a right-angle member.