A therapeutic device, therapeutic system and therapeutic method for myocardium repair, wherein the therapeutic device comprises a treatment needle for piercing the heart to release a therapeutant. The treatment needle includes a needle body (5a), the interior of the needle body (5) has a therapeutant conveying cavity, an end of the needle body (5a) is a needle (5b) which can pierce the myocardium and guide the needle body (5a) to pass through the myocardium, and the needle (5b) has a therapeutant output port which is connected to the therapeutant conveying cavity. The therapeutic device enters into the myocardium in a minimally invasive manner to release the therapeutant to the vicinity of the lesion to improve myocardial function or activity and prevent further deterioration of the disease.