Purpose: The research aims to explore prospective physics teachers' pedagogical knowledge (PK) through an online microteaching lesson study (OMLS). Design/methodology/approach: The study used a case study with eight prospective physics teachers. Various data sources are triangulated involving audiovisual meeting recording, documents from OMLS sessions, interviews, and observation. Findings: OMLS can build and enhance the PK of prospective physics teachers. The stages and cycles encourage participants to collaborate, exchange ideas to design active learning in the lesson plan teaching practice and revise deficiencies for improvement. The trial, analysis, discussion and revision of lessons reduced prospective teacher cognitive discrepancy. Research limitations/implications: This study has several limitations. First, the research only focuses on prospective physics teachers' PK with two cycles, limiting data collection and inaccuracies. Second, the data were taken qualitatively and from a relatively small group, so the findings are not generalizable. Practical implications: Educational departments in higher education can implement and develop various MLS models according to the conditions of their respective students. Originality/value This study realizes higher education as a preparation place for prospective teachers' future careers as professional teacher candidates.