The present invention provides a design method for circuit layout and a rapid thermal annealing method for a semiconductor apparatus. The design method includes: establishing a ternary relationship among a device electric parameter, an annealing temperature and a distributing density of STI patterns, and establishing a binary relationship between the device electric parameter and a gate pattern length; obtaining a difference between distributing densities of STI patterns in a particular region and in a target region; obtaining an electric parameter difference corresponding to the difference between the distributing densities of STI patterns according to the ternary relationship; obtaining a gate pattern length difference corresponding to the electric parameter difference according to the binary relationship; and adjusting a gate pattern length in the particular region according to the gate pattern length difference. As compared with a traditional design method, the design method for circuit layout provided by the invention does not need adding dummy structure patterns, thereby avoiding negative influence to normal electric performance of the semiconductor apparatus by adding dummy structures.