The invention discloses a method for writing a state register of a nonvolatile memory. The method comprises: step 1, reading original data of the state register; step 2, judging whether data sent by a user is the same as the original data or not, and if so, ending the writing of the state register, or otherwise, performing the step 3; step 3, judging whether the original data is all erasing data or not, and if so, performing programming operation on the original data, or otherwise, performing the step 4; step 4, judging whether the original data is all programming data or not, and if so, performing erasing operation on the original data, or otherwise, performing pre-programming operation and erasing operation on the original data and performing the step 5; and step 5, judging whether the user data is all the erasing data or not, and if so, ending the writing of the state register, or otherwise, performing programming operation on the state register and ending the writing of the state register. According to the technical scheme provided by the invention, the time for writing the state register is shortened and the service life of the state register is prolonged.