Disclosed is a multimode set top box and a mode management method thereof. The method includes: a multimode set top box using a first play resource to play in a main mode a channel program of a first service system associated with the main mode by default, and using a second play resource to play in an auxiliary mode a channel program of a second service system associated with the auxiliary mode by default; when receiving a mode switching instruction, keeping the first play resource and the second play resource in a non-released state, and keeping an accessing state with the first service system and an accessing state with the second service system; and using the first play resource to play in the auxiliary mode the channel program of the first service system, and using the second play resource to play the channel program of the second service system.