In the present study, a passive twist control is considered as a potential way to improve the overall flight efficiency for proprotor of Micro Air Vehicle (MAV). This paper will focus on the aerodynamic performance and deformation behaviour of a flexible laminate blade. Incorporated with a database of airfoil characteristics, Blade Element Momentum Theory (BEMT) is implemented for performance prediction of proprotor at low Reynolds numbers. The preliminary procedure is based on finding optimum twist distributions for hover and forward flight, but keeping a given chord distribution. A numerical model is developed using a combination of aerodynamic model based on BEMT, and structural model based on anisotropic beam finite element, in order to evaluate the coupled structural and the aerodynamic characteristics of the deformable proprotor blade. The numerical model - Fluid Structure Interaction (FSI) was then validated by means of shape reconstruction from LDS (Laser Displacement Sensor) outputs. It can be concluded that the proposed experiment technique is capable of providing a predictive and reliable data in blade geometry and performance for rotor mode. The FSI approach is also valid as a reliable tool for designing and analyzing the MAV proprotor made of composite material.