The aminated collagen fiber (ACF) was prepared by modifying collagen fiber (CF) with ethylenediamine and cynuric chloride as crosslinking agent. The appropriate modification conditions were optimized by single factor experiment method. The reaction molar ratio of CNC and -NH2 was 1.4, the reaction time of ice water bath was 3h, the temperature of the second phase was 45°C and the reaction time was 4h, the temperature of the third phase was 70°C and the reaction time was 3h. The content of amino of collagen fiber and aminated were measured by the method of salicylaldehyde. The structures of collagen fiber and aminated collagen fiber were characterized by SEM and FTIR respectively. The adsorption capacities and the content of amino of CF and ACF were observed by dealing with acidic black dyeing and sturgeon skin dyeing wastewater.