Based on human capital characteristics of a language, Q Value is introduced to quantify its economic value and to revise Grin Model for analyzing the necessity of the survival of minority languages. Analysis results show that the larger the Q value of a language, that is the stronger the vitality of the language is, the more time people invest in the language, that based on the reasons of culture and politics, under the premise of the necessity for protecting the minority languages, depicting the survival threshold of the minority languages and changing language attitudes and the percentage of people who speak the minority languages can make the minority languages change from mortality region to alive region and that in institutional arrangement of the protection of minority languages, adding the percentage of the people who speak the minority language is very important.