A glassy carbon electrode modified with TiO2NPs/RGO/AuNPs was used as an electrochemical sensor to detect trace amounts of 4-p-nitrophenol (4-NP). The surface morphology of the composites was characterized by field-emission scanning electron microscopy (FE-SEM). The electrochemical characteristics of the composite electrode were analyzed by cyclic voltammetry(CV) and electrochemical impedance spectroscopy(EIS). The modified electrode exhibited outstanding electrochemical performance due to the large specific surface area and strong conductivity of composite material. The differential pulse voltammetry(DPV) and square wave voltammetry(SWV) were used for the trace detection of p-nitrophenol. The peak current of the two methods showed a high linear relationship with the 4-NP concentration. The detection range applied DPV method was 0.5-100μmol/L, the detection limit was 0.03μmol/L. When SWV was employed, detection range was from 0.5 to 100μmol/L, The detection limit was 0.08μmol/L. In this study, the electrochemical sensor had the advantage of large detection range, low detection limit, stable, simple and fast analysis. Based on these characteristics, the sensor can be considered as a potential sensor for the detection of 4-NP.