The inner-formation gravity field measurement satellite was proposed to measure Earth's gravity field with high accuracy and spatial resolution through precise orbit determination and relative state measurement. Both techniques relied on precise formation control and accurate attitude control, during steady-state phase, where the relative displacement had to be suppressed down to centimeter, and the outer-satellite attitude had to be earth-oriented with 0.1 degree accuracy. The integrated orbit and attitude control aims to guarantee the scientific measurement during steady-state phase, applying micro-thrusters. The all-propulsion design was processed on a coupled linear model with thruster layout; the integrated orbit and attitude control was implemented based on model predictive control (MPC) algorithm. Simulation results demonstrate the feasibility and validity of this integrated control scheme with micro-thrusters.