The semi-quantum communication protocol allows participants with only limited quantum capabilities to carry out quantum communication. Compared with the full quantum communication protocol, it reduces the loss of quantum resources and saves the costs of quantum hardware. Based on a semi-quantum model, a novel semi-quantum private comparison protocol is proposed with the four-particle Greenberger-Horne-Zeilinger (GHZ) state as the quantum resource state. The protocol can compare the information of two classical users, Alice and Bob, with the help of a semi-honest third party without disclosing their secret information. Security analysis shows that this protocol can resist both internal and external attacks. Compared with the existing semi-quantum private comparison protocol, the classical user in the proposed protocol requires less quantum capability, only needs to perform Z-based measurement and reflect the received particles, and has high quantum bit efficiency. In addition, the proposed protocol is verified by simulation experiments on IBM quantum cloud platform.