The present invention discloses a point-type multi-electrode array capacitive sensor for position and orientation measurement of a welding gun. The sensor comprises excitation electrodes, receiving electrodes, a shielding cover, an insulation layer and a tiny capacitance measurement circuit, etc. Each set of excitation electrodes and the receiving electrodes are located at the same plane, the effective detection edge effect between each set of excitation electrodes and the receiving electrodes and the corresponding electrode plates are located at the same plane, and the effective edges of each set of electrode plates are parallel with each other. When the position and orientation measurement of the welding gun, each set of electrode plates are configured to perform signal collection of welding seam areas in order, and the tiny capacitance measurement circuit is configured to perform processing of the data collected by each set of the electrode plates through adoption of the integral ratio method so as to calibrate the center of the welding seam and determine the transverse and vertical directions of the welding gun and the space angle position deviation and obtain the optimal space position and orientation of the welding gun.