The spin-orbit coupling interaction， Zeeman effect and interface microroughness effect in an HgCdTe inversion layer were investigated by experimental measurement. Theoretical models were used to analyze the weak antilocalization （WAL） at different temperatures and in different in-plane magnetic fields. It is found that both the Zeeman effect and the interface microroughness effect will suppress the WAL. And the interface microroughness effect takes effect by facilitating a weak localization in the normal direction of the two-dimensional electron gas （2DEG） plane. With the increasing magnetic field， the interface microroughness induced WL will be suppressed first and then the WAL will be suppressed by Zeeman effect. What’s more， the analysis of parameters τ/τ? and mr*g3* indicates that the Zeeman effect’s suppression on WAL does not depend on temperature.