A population-based, longitudinal study was conducted among 29 provinces in mainland China to investigate how public trust in physicians (PTP) changed since the outbreak of COVID-19 and how the resulting lockdown and social support contributed to its restoration. The baseline sample (n = 3,233) was obtained during the period of the most rapid progression of COVID-19 (February 1 to 9, 2020, T1). Follow-up (n = 1,380) took place during the recovery period (March 17 to 24, T2). Latent profile models and a latent transition model were estimated. Participants were classified into either a moderate trust (21% at T1; 45% transition into high at T2) or a high trust (79% at T1; 88% remained in the high group) group in the latent profile. A latent transition from moderate to high trust was observed in locked-down regions and among those with higher social support. Social support moderated the transition from low to high trust. The current study showed that the epidemic outbreak and lockdown experience in China were associated with increased PTP; furthermore, public trust can be restored during a public health emergency. Attention should be paid to assure that social support and risk management strategies maintain PTP.