Ethanol is a relatively complex molecule which presents broadband absorption spectra at atmospheric pressure,its stretching overtones of OH bond is around 70007300 cm-1. The absorption spectrum of ethanol vapor with small amount of water vapor near 7180 cm-1 was acquired by adopting tunable diode laser absorption spectroscopy (TDLAS) method, an absorption feature with HWHH of approximately 1.3 cm-1 was obtained by eliminating the interference of water vapor with polynomial fitting. Study on the line-types of absorption spectra of ethanol vapor with different concentrations demonstrates that line-types have no dependence on partial pressure. This work laid the foundation for the research of ethanol remote sensing based on TDLAS.