Background We aim to assess the learning curve of robotic portal lobectomy with four arms (RPL‐4) in patients with pulmonary neoplasms using prospectively collected data. Methods Data from 100 consecutive cases with lung neoplasms undergoing RPL‐4 were prospectively accumulated into a database between June 2018 and August 2019. The Da Vinci Si system was used to perform RPL‐4. Regression curves of cumulative sum analysis (CUSUM) and risk‐adjusted CUSUM (RA‐CUSUM) were fit to identify different phases of the learning curve. Clinical indicators and patient characteristics were compared between different phases. Results The mean operative time, console time, and docking time for the entire cohort were 130.6 ± 53.8, 95.5 ± 52.3, and 6.4 ± 3.0 min, respectively. Based on CUSUM analysis of console time, the surgical experience can be divided into three different phases: 1–10 cases (learning phase), 11–51 cases (plateau phase), and >51 cases (mastery phase). RA‐CUSUM analysis revealed that experience based on 56 cases was required to truly master this technique. Total operative time (p < 0.001), console time (p < 0.001), and docking time (p = 0.026) were reduced as experience increased. However, other indicators were not significantly different among these three phases. Conclusions The RPL‐4 learning curve can be divided into three phases. Ten cases were required to pass the learning curve, but the mastery of RPL‐4 for satisfactory surgical outcomes requires experience with at least 56 cases. The learning curve of RPL‐4 can be divided into three phases. Ten cases were required to pass the learning curve, but the mastery of RPL‐4 for satisfactory surgical outcomes requires experience from at least 56 cases.