High-entropy alloys (HEAs) generally possess complex component combinations and abnormal properties. The traditional methods of investigating these alloys are becoming increasingly inefficient because of the unpredictable phase transformation and the combination of many constituents. The development of compositionally complex materials such as HEAs requires high-throughput experimental methods, which involves preparing many samples in a short time. Here we apply the high-throughput method to investigate the phase evolution and mechanical properties of novel HEA film with the compositional gradient of (Cr,Fe,V)–(Ta,W). First, we deposited the compositional gradient film by co-sputtering. Second, the mechanical properties and thermal stability of the (Cr0.33Fe0.33V0.33)x(Ta0.5W0.5)100?x (x = 13–82) multiple-based-elemental (MBE) alloys were investigated. After the deposited wafer was annealed at 600°C for 0.5 h, the initial amorphous phase was transformed into a body-centered cubic (bcc) structure phase when x = 33. Oxides were observed on the film surface when x was 72 and 82. Fi-nally, the highest hardness of as-deposited films was found when x = 18, and the maximum hardness of annealed films was found when x = 33.