Basalt fiber is one of the best reinforcing materials and satisfies all the needs of a composite material. Flax is predominately used natural fiber which has better mechanical and sudden load shock-absorbing properties. The general-purpose polyester resin in one an excellent binding agent which equally distributes the load along the direction of applications. To understand the mechanical properties of the natural and synthetic fiber of these flax/basalt fiber combinations is essential to reduce the usage of synthetic fibers. In this paper, the maximum tensile strength was found on the combination of pure 10 layers of basalt and it was about 185MPa. The maximum flexural strength absorption was seen in the combination of 10 layers of basalt fiber composite about 190MPa. The maximum impact energy was absorbed by composite D, the alternative layers of basalt and flax fiber composite. SEM analysis shows with matrix cracking, and fiber twist was seen, this is because of the improper mixing of the fiber and matrix shows this type of internal failure, the fiber pulls out and blow holes in between the fiber and matrix also seen in the composites.