The invention discloses a functional food for promoting growth and development of children and a preparation method thereof. The method comprises the following process steps of raw milk selection, rawmilk storage, milk clarification and standardization, cooling storage, other raw material preparation, blending, preheating, homogenization, sterilization and concentration, spray drying, fluidized bed performance, powder sieving, and packaging. The functional food comprises the following raw materials in parts by weight: 10-15 parts of sea cucumber powder, 5-20 parts of hawthorn fruit powder, 3-5 parts of chicken's gizzard-membrane powder, 5-8 parts of stachyose, 3-5 parts of amino acid calcium, (0.3x10<-3>)-(0.5x10<-3>) part of vitamin A, 0.1-0.3 part of vitamin C, (1.5x10<-6>)-(3x10<-6>) part of vitamin D, (0.4x10<-3>)-(1x10<-3>) part of vitamin B2, 0.6-1 part of zinc lactate, and 40-95 parts of bovine colostrums. The food is scientific in formula and comprehensive in nutrients. The preparation method of the invention is reasonable in process, feasible in operation and easy to realize large-scale production.