The invention discloses an environment-friendly dope-dyed polyamide fiber. The environment-friendly dope-dyed polyamide fiber comprises, by mass, 10 to 15 parts of a high-shrinkage terylene slice, 80 to 90 parts of a high-transparency terylene slice, 5 to 10 parts of titanium dioxide, 10 to 20 parts of an environment-friendly dye and 20 to 40 parts of polyester polyol. A preparation process provided by the invention enables the polyamide fiber to be uniform in color quality, high in color fastness and not prone to fading, reduces dyeing cost, lowers consumption of water and energy in the procedure of dyeing, decreases pollution, is beneficial for environmental protection and meets requirements of development of circular economy.