A vented heat pump dryer, comprising: an outer drum, an air-intake drying air duct and an air-exhaust drying air duct for allowing communicating the outer drum with outside respectively. The dryer is also provided with a heat pump system. A condenser of the heat pump system is arranged in the air-intake drying air duct, and an evaporator is arranged in the air-exhaust drying air duct. The air-exhaust drying air duct comprises at least two branches capable of being controlled to open and close. Each branch is provided with a corresponding evaporator. At different drying stage, the dryer makes exhaust air stream flow through different branches independently or at the same time, so that can adjust the working states of the heat pump reasonably and increase the drying efficiency of the dryer.