Carbonate reservoirs are primary targets for deep geothermal energy exploitation, but those with large thickness and great burial depth are generally characterized by low permeability, necessitating stimulation to improve productivity. Acidizing is a mature technique widely applied to plug removal in near-wellbore zones and conductivity enhancement in such reservoirs. Nevertheless, it faces challenges such as severe fluid loss and a limited effective treatment radius, making it urgent to develop new technologies to address these problems. Five mainstream stimulation technologies, namely acidizing, liquid nitrogen fracturing, supercritical carbon dioxide fracturing, high-energy gas fracturing and hydraulic jetting are reviewed in this paper. Special focus is placed on acidizing, encompassing its research background, influencing factors, and field applications in carbonate reservoirs. The mechanisms, application conditions, and advancements of the other four technologies are also elaborated on. The advantages and drawbacks of each technology are compared in terms of fracture network propagation, engineering implementation, and economic cost. Meanwhile, the feasibility and future prospects of their deployment in carbonate reservoirs are discussed. The effectiveness of hydraulic jet acidizing stimulation is analyzed in detail through a practical case study. It is found that acidizing is widely adopted for its low cost and technological maturity, and its combination with hydraulic jetting can effectively expand the treatment range. Liquid nitrogen and supercritical carbon dioxide fracturing can reduce the breakdown pressure and form relatively complex fracture networks, but they are confronted with problems like high cost and weak proppant-carrying capacity. High-energy gas fracturing is well-suited for brittle formations, producing wide but relatively short fractures. Given the characteristics of deep carbonate geothermal reservoirs such as low permeability and high temperature, it is recommended to optimize the acid fluid system and improve the acidizing operational procedures. In the future, efforts should focus on improving stimulation effectiveness by developing combined technologies, optimizing construction parameters, promoting cost reduction and conducting field tests. Meanwhile, in response to the demands of deep geothermal energy exploitation, research should be conducted including basic geological surveys, integration of experiments and simulations, and the establishment of technical standards, so as to underpin the large-scale and efficient development of low-permeability carbonate geothermal reservoirs.