Mastering the national common language is essential for pre-school children in ethnic minority areas to receive modern education and adapt to modern society; it is also an important approach to improve the shared Chinese community awareness, to inherit and develop fine traditional Chinese culture, and to promote ethnic unity and development. With regard to the present problems with the evaluation standard of pre-school children''s national common language proficiency in Liangshan prefecture, such as unclear goal orientation, unknown age stage, fewer assessment contents, reasonableness to be improved, ambiguous points of evaluation, etc. This paper, taking into account the programmatic documents on preschool children development, puts forward from the collaborative perspective the advices to help functional departments of Liangshan Prefecture to accurately grasp the essentials of the goals of language development of preschool children, and to formulate and improve the national common language assessment standards for preschool children of different ages.