The invention discloses a car door support of an electric car. The car door support comprises a car door frame and a car door. The car door support comprises a left longitudinal beam and a right longitudinal beam which are fixed to the two sides of the car door. The right longitudinal beam extends towards the direction of the left longitudinal beam, and thus a cross beam is formed. The cross beam comprises a short rod, an oblique rod and a long rod, wherein the short rod is fixed to the right longitudinal beam, the oblique rod is formed in the mode that the end of the short rod outwards and obliquely extends out in the horizontal direction, and the end of the oblique rod extends to the left longitudinal beam to be fixed to the long rod. A hinging fixed rod is arranged on the lower portion of the left longitudinal beam. A fixed inserting rod is arranged in the position, matched with the hinging fixed rod, on the car door frame. A limiting belt is connected between the hinging fixed rod and the fixed inserting rod. The car door support is simple in structure, the car door is reinforced, and the car door can be further protected against being turned over excessively.