The invention discloses a milk replacer for stimulating calf rumen development and a feeding method thereof. The milk replacer consists of calfmeal and a calf starter. The calfmeal in the invention contains soluble dietary fiber able to maintain calf intestinal health, body immunity improving and palatability adjusting substances. Especially starch and particles in the starter have certain hardness which can promote the rumen nipple development of calves, and enough digestible fiber in the starter can support the normal proceeding of rumen fermentation, so that calves can be guaranteed to get nutrients necessary for growth and development from solid forage early, and the calf constitution can be improved, the disease resistance is enhanced, and the daily weight gain as well as the feed intake for solid forage are raised. With obvious feeding effect, the milk replacer of the invention has convenient raw material resource, rational price, and can reduce the feeding cost of calves and obtain great economic benefit. 350kg of fresh milk is needed for breeding a calf, while with the milk replacer, 300kg of fresh milk can be saved by each calf. Calves fed with the milk replacer provided in the invention can be weaned in 40 days, therefore, the feeding cost can be directly saved by 174.95 yuan by each calf.