The space-based gravitational wave detectors at low frequencies has received great attention recently. Due to lack of considering the relative motion between spacecrafts, the accuracy of current sensitivity models is inadequate for space-based gravitational wave detectors. In this paper, an accurate sensitivity model of the space-based gravitational wave detector is established by taking into account the relative motion between two spacecrafts. The accurate sensitivity model is derived by employing a gravitational wave perturbed metric tensor. Then, to minimize the sensitivity loss due to the solar radiation, an enhancement strategy is proposed. Finally, simulation studies are presented with two drag-free spacecrafts in Earth’s orbit. Simulation results validate the effectiveness of the proposed strategy.

低频的空基重力波探测器最近受到了极大的关注。由于缺乏考虑航天器之间相对运动的能力，因此当前灵敏度模型的精度不足以用于天基重力波探测器。本文通过考虑两个航天器之间的相对运动，建立了精确的天基重力波探测器灵敏度模型。精确的灵敏度模型是通过采用重力波扰动的度量张量得出的。然后，为了最小化由于太阳辐射引起的灵敏度损失，提出了一种增强策略。最后，对地球轨道上的两架无阻力航天器进行了仿真研究。仿真结果验证了所提策略的有效性。