The present invention discloses a polyvalent metal ion compound salt of N,N-dimethylglycine and organic acid or a solvate thereof, and use thereof in preparing novel feed additives and feed; the present invention also discloses a composition comprising the polyvalent metal ion compound salt of N,N-dimethylglycine and organic acid or the solvate thereof. The polyvalent metal ion compound salt of N,N-dimethylglycine and organic acid or the solvate thereof provided by the present invention has improvement effect on animal product performance such as improving animal weight gain and reducing feed conversion ratio, showing effects similar to or higher than that of sodium N,N-dimethylglycinate.