A method for resource allocation and a terminal device are provided. The method includes the following operations. An operating system of a terminal device receives a scenario data packet of a photography application that is currently running on the terminal device, where the scenario data packet includes a performance improvement strategy determined by the photography application according to a running scenario. The operating system acquires the performance improvement strategy by analyzing the scenario data packet. The operating system adjusts allocation of system resources for the photography application according to the performance improvement strategy.