The fluid-structure interaction (FSI) between the canopy and flow field on the inflating and inflated conditions is investigated based on the arbitrary Lagrange-Euler (ALE) method, in both a single-and double-cruciform parachute systems. The projection area of canopy is calculated in the inflation process. The flow field characteristics and the interaction between canopies are analyzed. Results showed that, with free stream velocity of 50 m/s, overinflation phenomenon would not occur during the inflation process of the double-cruciform-parachute system, because the collision and extrusion of the two canopies during inflation obstructed the oscillation of the inner gores. Concurrently, compared with the single-cruciform parachute, the vortex motion in the wake of double-cruciform-parachute is more intense. Thus the double-cruciform parachute system oscillated at a velocity of 50 m/s with an angle of less than 6.8°. By comparison, the oscillation angle of the single-cruciform parachute was within 3.5° at the velocity of 50 m/s. The results are consistent with those of the wind tunnel test.