The invention discloses a leg muscle massage relaxing device for physical exercise. The leg muscle massage relaxing device for physical exercise includes a base, a column and a top plate. The upper surface of the base is provided with the column. A seat cushion is arranged at the upper surface of the base at on one side of the column through two support legs, and a backrest is arranged at one sideof the seat cushion near the column. Both sides of the backrest are rotatably connected with armrests through rotating shafts, the backrest is provided with a trough body, the inner cavity of the trough is provided with a back massage device, when the user needs to massage the leg muscles after the exercise is completed, the user firstly sits on the seat cushion, puts the legs on a support table,and adjusts a height of a support table by starting an electric telescopic rod to achieve a comfortable position for the user, a massage roller can contact the user's leg to start a first motor, so that the first motor continues to make a positive and negative rotation, and a threaded rod is rotated.