We present and establish a seafloor deformation model for gas hydrate exploitation in the sea area based on Okada’s linear elasticity theory. The seafloor deformation field is simulated by using high precision tiltmeters, and the model parameters are inverted by simulated annealing method. The results show that the accurate information of dip, azimuth and volume of hydrate dissociated zone can be obtained by tiltmeters. The test results at different noise levels show that the model parameter inversion method has good anti-noise performance. In addition, the feasibility of tiltmeter monitoring in practical application is analyzed according to the hydrate exploitation test in Shenhu area of South China Sea in 2017, and the results show that the type of decline in production has advantages in seabed stability.