The invention relates to a movable-type heat preservation device for mountain tunnel winter construction of a severe cold region. The movable-type heat preservation device comprises a tank body, an opening is formed in the top of the tank body, wheels are arranged at the bottom of the tank body which is provided with a first head cover and a second head cover, the first head cover is fixedly connected with the tank body, the second head cover is movably connected with the tank body, and a water inflow and outflow opening is formed in the first head cover. By means of the movable-type heat preservation device for the mountain tunnel winter construction of the severe cold region, a water tank can provide construction water for a mountain tunnel construction operation region of the severe cold region, and it can be guaranteed that the construction water is kept at an appropriate construction temperature simultaneously.