The study of gas hydrate researched by the ice powder method is helpful for us to understand the storage, separation, transportation and transformation of gas on the solid surface. In this work, the change regulation has been studied that temperature, pressure, hydrate saturation, and conversion rate in the formation process of methane-ethylene mixed hydrate, which exploring the internal action mode of the methane-ethylene mixed hydrate. The experimental results show that under the condition of −4.0 °C and 4 MPa, the conversion rates of methane, methane-ethylene (with mole ratios 2, 1, and 0.5), and ethylene hydrate are 5.30%, 11.95%, 16.57%, 19.93%, and 26.84%, respectively. And more, the conversion efficiencies of hydrate are 0.36, 0.81, 0.96, 1.58, and 6.58, respectively. The above data show that with the increase of ethylene content, the formation of hydrate is easier, which proves that ethylene can promote the formation efficiency of methane hydrate. The above results have reference value for understanding the formation of natural gas hydrates, so as to promote the development and application of gas hydrate. • There is no induction period in the process of ice powder generating methane, ethylene, and methane-ethylene mixed hydrate. • The ethylene molecules in the methane hydrate formation process can increase the reaction rate of the system. • It provides theoretical support for the development and utilization of natural gas hydrates.