Aiming at the characteristics of high power consumption and abundant waste heat resources in data centers, the integrated energy systems of data center are constructed by combining CO2 heat pump and compressed CO2 energy storage. Considering different stages of compression and expansion in energy storage, System I and System II are proposed. The systems can continuously provide cooling to data center through the CO2 heat pump, and can also store the low-cost electricity so as to supply power to data center during the peak electricity consumption period. Meanwhile, hot water can also be provided by fully extracting the residual heat from the systems. Furthermore, to investigate system performances, the thermal and economic models are developed. On this basis, the thermal and economic performances for the two systems are analyzed in detail under design conditions. The results indicate that when providing cooling capacity of 5000 kW for data center, the Coefficient of Performance (COP) of heat pump is 7.22, and Round-Trip Efficiency (RTE) of System I and System II are 56.94 % and 55.85 % respectively. Systems I and System II can provide 879.26 tons and 1158.73 tons of domestic hot water, respectively. The total system capital cost is 234.35 × 104$ for System I, and 344.45 × 104$ for System II. Accordingly, the payback periods are 12.71 years and 11.19 years respectively. Furthermore, the effects of pressures on the system performances are also analyzed. The results show that every 0.5 MPa increase for heat pump outlet pressure, RTE of System II increases by 0.6 %, but the effect on System I is not significant.