The utility model discloses a computer heat dissipation sheet copper welding plate with the mistakenly-mounting prevention function. A square plate is formed by stamping a hot-dip galvanized steel plate, and each of the four corners of the square plate extends outwards to form a mounting platform; a downwards recessed square copper sheet welding zone is formed in the middle of the front surface of the square plate, and press lines are formed in the copper sheet welding zone; a parallelogram groove is formed in the copper sheet welding zone; two corners of the long diagonal line in the parallelogram groove are overlapped with two corners in the copper sheet welding zone, and flanged edges which are in the same extending direction as the parallelogram groove and face to the back surface are respectively arranged on the two side edges of the parallelogram groove; two mounting holes in the same side of the parallelogram groove are connected through downwards recessed reinforcing ribs; different mistakenly-mounting prevention sequence numbers are engraved in the positions, which are close to the four mounting holes, of the reinforcing ribs. The welding plate has the characteristics of simple structure, reliable strength, convenience for mounting, compactness, capability of mistakenly-mounting prevention and the like.