A traction mechanism, a bogie assembly and a straddle-type monorail vehicle are disclosed. The traction mechanism comprises: a traction component, comprising a traction connecting rod, a first crank and a transmission shaft, the traction connecting rod being suitable to be hinged to a bogie frame, a first end of the first crank being hinged to the traction connecting rod, a second end of the first crank being fixedly connected to the transmission shaft, and the transmission shaft being suitable to be rotatably connected to a vehicle body; and a traction crank, both ends of the traction crank being suitable to be respectively hinged to the bogie frame and the vehicle body, wherein the first end of the first crank is away from the traction crank. The traction mechanism of the present disclosure has a simple and compact structure, and a transmission path of a traction force is short. The traction mechanism is convenient to assemble and disassemble, occupies a small space, is wide in usage range, can be used for low-floor and high-floor vehicles, and is also applicable to a single-axle bogie, a double-axle bogie and a multi-axle bogie.