The invention discloses a truncated dummy module for an impact test. The truncated dummy module comprises two thigh artificial limbs and a waist hip artificial limb. The two thigh artificial limbs and the waist hip artificial limb are integrally formed. The face where the two thigh artificial limbs are located is perpendicular to the face where the waist hip artificial limb is located. The inclined angle between the back face of the waist hip artificial limb and the perpendicular face ranges from 9 degrees to 10 degrees. The inclined angle between the front face of the waist hip artificial limb and the perpendicular face ranges from 3 degrees to 4 degrees. The dummy module is made of expandable polystyrene. According to the formula of the expandable polystyrene, the expandable polystyrene comprises, by weight, 83% to 90% of polystyrene, 0.3% to 1% of talcum powder, 1% to 1.8% of hexabromocyclododecane flame retardants, 0% to 0.15% of maleic acid organic tin, 0.3% to 0.7% of benzal sorbitol, 3% to 8% of ClF2CH3 and 3% to 8% of CH3C1. According to the truncated dummy module, the lower limbs and the trunk are combined and similar to a human body, the requirement of a dummy special for a motor vehicle impact test is met on the aspect of performance, and the cost is lower.