The inlet temperature of the Vacuum Gas Oil (VGO) hydrotreating reactor of a refinery is analyzed with the integration of multiple series reactors and hydrogen network considered. The effect of the inlet temperature (T-1) on hydrogen sinks/sources and the product output is analyzed systematically based on the simulation of the series reactors, including VGO hydrotreating reactor, hydrocracking reactor, fluid catalytic cracking reactor and visbreaking reactor. The general relation between the Hydrogen Utility Adjustment (HUM) and multiple pairs of varying sinks and sources is deduced, and correlations between varying streams and T-1 are linearly fitted. Based on this, the quantitative equation between HUA and T-1 is derived, and corresponding diagram is constructed. The T-1 corresponding the minimum hydrogen consumption is identified to be 345 degrees C. (C) 2019 The Chemical Industry and Engineering Society of China, and Chemical Industry Press Co., Ltd. All rights reserved.