Thermal management system and control method thereof

A thermal management system, comprising a first liquid pipeline, a second liquid pipeline and a switching valve group, wherein

• a first heat exchange unit, a first circulation pump and a first heat exchange device are connected in series on the first liquid pipeline;
• a second heat exchange unit, a second circulation pump and a second heat exchange device are connected in series on the second liquid pipeline;
• the switching valve group is connected between the first liquid pipeline and the second liquid pipeline;
• the switching valve group is configured to be switched between a first working position and a second working position, and in a case that the switching valve group is in the first working position, liquid flow circulations of the first liquid pipeline and the second liquid pipeline do not interfere with each other, and in a case that the switching valve group is in the second working position, the first liquid pipeline and the second liquid pipeline are connected in series.