A measuring tape for measuring the size of limbs or waists is provided with a tape head capable of being stably inserted into a positioning hole during measurement and being automatically ejected out of the positioning hole after measurement, and includes a shell, and a cavity formed in the shell and used for receiving a flexible rule. An elastic switch assembly for clamping the tape head in the positioning hole is disposed at a position, close to the positioning hole, in the cavity. The elastic switch assembly and a leaf spring are disposed in the positioning hole, allowing the tape head to be inserted thereinto, in the shell, such that the tape head can be stably disposed in the positioning hole after being inserted into the positioning hole, and will not slide out of the positioning hole when users observe measure data.