The invention relates to the technical field of computer peripheral keyboards, and particularly relates to a mechanical keyboard key switch provided with a replaceable base, which comprises a key switch and a key cap arranged at the upper end of the key switch, wherein the lower end of the key switch is provided with a base detachably connected with the circuit board of the mechanical keyboard. When the key switch and the base are damaged, replacement is convenient, a user does not need to use special tools such as an electric iron, automatic replacement can be realized, depot repair is not needed, the repair cost is reduced, time and labor are saved, resource waste is avoided, and the freedom degree of the user to perform keyboard part replacement, updating and DIY can be improved.