Abstract: Nuclear fuel cladding is the first safety barrier of the reactor. For additional safety of the fuel assemblies under accident conditions, accident tolerant fuel (ATF) cladding material has been widely noted. Chromium-coated (Cr-coated) fuel cladding becomes the mainstream solution of ATF cladding in the domestic and foreign related research. Cr-coated fuel cladding has the advantages of reducing the zirconium oxidation at extremely high temperatures (over 1 200 ℃) and increasing the survivability of the cladding material for short critical heat flux (CHF) transients, which make it an alternative to conventional reactor fuel cladding. In this paper, the experimental study on CHF limits of the Cr-coated fuel cladding under high pressure flow boiling conditions was presented. For these experiments, uniformly electronic heater rods were used to simulate nuclear fuel rods, and experiments were performed with single-heater rod and 5×5 heater rods assemblies (Cr-coated and conventional surfaces) respectively under prototypical conditions of pressurized water reactors to study the effect of Cr metal coating on the CHF limit of the fuel cladding. Any discrepancies between the CHF verified among the cladding materials are attributed to departure from nucleate boiling phenomena captured during the experiments with the high-resolution thermocouple temperature data. The main parameters that affect the CHF experimental result are inlet temperature, inlet flow rate, outlet pressure and the rod structure parameters. In order to avoid the influence of factors other than the chromium coating on the experimental results, ensure that the external diameter, length and surface roughness of the heater rods (Cr-coated and conventional surfaces) are excactly the same. Besides, the initial conditions of the two kinds of experiment sections (Cr-coated and conventional surfaces) before the linear power rise were adjusted to make them as close as possible. The results of experimental investigations show that difference of CHF experimental values of Cr-coated heater rod compared with that of conventional heater rod under the same experiment conditions (up to 15.5 MPa) is within the range of ±5%. The critical power of Cr-coated 5×5 heater rods assembly under the same high pressure flow boiling conditions (up to 17.5 MPa) compared with that of the conventional 5×5 heater rods assembly, the difference is between ±6%. In summary, the CHF experimental values of Cr-coated and conventional surfaces indicate that there is practically no difference in the CHF limits, which provides experimental study basis for Cr-coated fuel cladding in pressurized water reactors.