The invention relates to a denatured protein powder and a brain protein hydrolyzate prepared from the same. The total nitrogen content of the denatured protein powder is more than 120 mg/g; and the denatured protein powder is prepared by adding fresh lysozyme into a pig brain, homogenating, heating, and defatting with acetone. The denatured protein powder, as a raw material, is used for preparingthe brain protein hydrolyzate; the contents of amino acids in the prepared brain protein hydrolyzate meet national standards of brain protein hydrolyzate injections; and the content of small moleculepeptides with the molecular weight of less than 10000 Da is 25-35% of the brain protein hydrolyzate. The preparation method of the brain protein hydrolyzate mainly comprises the following steps: pre-treating, homogenizing, defatting with the acetone, performing dual enzymatic hydrolysis, centrifugating, refining by column chromatography, and performing ultrafiltration treatment. The invention discloses key technical points for controlling the total nitrogen index of the protein powder and the content of the small molecule peptides for the first time; the obtained brain protein hydrolyzate is a biologically active substance which is really extracted from the pig brain, without adding active components artificially, thus ensuring the efficacy and the safety of the brain protein hydrolyzate;and animal pharmacodynamic experiments show that the brain protein hydrolyzate is more effective than conventional products.