Frequency diversity array (FDA) has great advantages in radar detection and imaging. However, when FDA is applied to Inverse Synthetic Aperture Radar (ISAR), the automatic scanning characteristic of FDA has become one of the key problems to be solved. In order to solve this problem, this paper applies the FDA continuous focused tracking beam technology to ISAR imaging, and realizes the FDA-ISAR imaging with high energy accumulation. Firstly, pulse signals are repeatedly transmitted to targets at different times and angles through this technology, and then the echo of the tracking beam is phase compensated. Finally, the fast Fourier transform algorithm is used to complete two-dimensional imaging. The simulation results show that the gain effect of energy superposition can be achieved by using the continuous focusing tracking beam, and the FDA-ISAR imaging system combined with this technology can achieve two-dimensional imaging of moving targets.