In this paper, the electron transports through a three-barrier nanowire heterostructure between two reservoirs with different temperatures and chemical potentials are studied. The transport probability of electron is obtained by using the transfer matrix method,and the heat flow carried by the electrons transfer is calculated out. The performance characteristic curves of the refrigerator are plotted by numerical calculations. The influence of bias voltage and heterostructure on the performance of the refrigerator is analyzed. Especially, the effects of the height and the width of the middle barrier on transport probability, cooling rate, and colling coefficient are emphasized.