The present invention relates to the static characteristic optimization technology field, and discloses a magnetic resistance static characteristic optimization method based on the internal bias field hard direction. The method concretely comprises the following steps: the step 1, setting an easy axis bias field as a steady state value, and setting the value of a hard-axis bias field to obtain a sensing curve; the step 2, selecting the maximum value hFM of a special magnetic field measurement range, optimizing the sensing curve through a target function, and obtaining a sensitivity k, a bias b and an absolute error Err; the step 3, selecting the maximum values hFM of different magnetic field measurement ranges, and repeating the step 2; the step 4, selecting the values of different hard-axis bias fields, repeating the steps 1-3, and obtaining the relation curve of N absolute errors Err at the same two-dimensional coordinates A and the magnetic field measurement ranges; and the step 5, obtaining the special magnetic field measurement range of the two-dimensional coordinates and the corresponding value of the hard axis-bias field with the minimum absolute value in the special easy-axis bias field according to the two-dimensional coordinates. The magnetic resistance static characteristic optimization method based on the internal bias field hard direction can obtain a bigger range of linearity through regulation of the hard-axis bias field.