Starting the proton exchange membrane fuel cell (PEMFC) stack from subfreezing temperatures is a remaining challenge for the commercialization of PEMFC vehicles. This paper aims to provide an efficient cold start strategy for PEMFC stacks to meet the requirements of rapid, safe and efficient startup in a wide range of subfreezing temperatures. Herein, an efficient cold start strategy combines the advantages of self-starting and coolant heating is proposed and validated in terms of startup time, voltage consistency and energy consumption. Results demonstrate that self-starting from −20 °C is achieved within 30 s. Rapid and safe cold-start from −30 °C and −40 °C is also realized within 82 s and 100 s, respectively. The target heating temperature of −20 °C is optimal for this strategy. The voltage consistency of the stack during cold start is closely related to cold start performance, and is affected by the starting temperature and the heating power. The stack voltage consistency increases with the increase of starting temperature and heating power. Energy conservation calculations indicate that the heating power should match the stack temperature to avoid excessive energy consumption and insufficient heating. This paper provides an efficient solution for cold starting of a hybrid PEMFC system.