Λ-enhanced gray molasses cooling (Λ-GMC) technique has been widely used in experiments to prepare cold atomic samples below the sub-Doppler temperature limit. To meet the experimental requirements of cavity quantum electrodynamics systems, we design and construct a wide-range, fast-tuning laser system by integrating tapered amplifiers, fiber phase modulators, etalon, injection locking amplification techniques etc. This laser system achieves a maximum tuning range of 600 MHz and a frequency tuning speed of 5 ns. Based on this laser system, loading atom in a crossed dipole trap assisted by cesium D2 line Λ-GMC cooling in the center of the optical microcavity is studied, and various factors affecting the atom loading are mainly as follows: laser duration \tau , three-dimensional magnetic field \left( B_x, B_y, B_z \right) , single-photon detuning \varDelta , two-photon detuning \delta , ratio of cooling beam power to repumping beam power I_\textcool/I_\textrep, and cooling beam power I_\textcooling. The optimal parameters in this system are follows: \tau = 7\text ms,\; \delta = 0.2\text MHz,\; \varDelta = 5\varGamma, \;I_\textcool/I_\textrep = 3, \text and I_\textcool = 1.2I_\textsat. Comparing with traditional PGC-assisted loading, the number of atoms is increased about 4 times, and the atomic temperature decreases from 25\text μK to 8\text μK . This experiment provides important insights for preparing ultracold atomic samples and capturing single atom arrays.