The present invention relates to the technical field of biomedical engineering, and provided thereby is a use of an RyR2 protein or RyR2 recombinant protein in preparing anti-heart failure medicine; an RyR2 recombinant protein is a fragment or mutant of a naturally occurring RyR2 protein, and may be, for example, a SPRY1 structural domain protein, a P1 structural domain protein, a SPRY2 structural domain protein, a SPRY3 structural domain protein, a Handle structural domain protein, an HD1 structural domain protein, an HD2 structural domain protein, a central structural domain protein, an EF-hand structural domain protein, a U-type motif protein, a P2 structural domain protein, a P2 structural domain fragment protein 1, a P2 structural domain fragment protein 2 or a RyR2 protein P2 mutant of a natural RyR2 protein; the exogenous RyR2 recombinant protein has high expression levels in both a normal small animal model and a small animal disease model such that the left ventricular ejection fraction in experimental animals experiences different degrees of improvement compared to a control group, while β-adreno-triggered ventricular tachyarrhythmia in animals in the disease model is decreased to different degrees, and the cardiac function of each treatment group is recovered to different degrees.