While principal leadership has been exercised in day-to-day practices to address the needs of teachers as professional learners, empirical studies regarding its effects on teacher professional learning have not increased proportionally. Using a sample of 255 secondary school principals and 2756 teachers from four provinces of Beijing, Shanghai, Jiangsu, and Guangdong in China (B-S-J-G-China) who participated in the 2015 Program for International Student Assessment (PISA 2015), this study employed a two-level hierarchical linear modeling to examine principal leadership effects on teacher professional learning. Results showed that principal leadership practices explained a large proportion of between-school variance in teacher learning. Principals' developing people had positive effects on both personal and collaborative learning. Principals' instructional improvement had a positive effect on collaborative learning, while principals' facilitating teacher participation had a negative effect on collaborative learning. The implications for improving principals' role in promoting teacher learning are also discussed.