As an internal combustion engine fuel, hydrogen had been acknowledged by international auto industry to be a possible practical and economical fuel for automobile in the future. Port fuel injection is currently considered as the easiest way for hydrogen-powered vehicle application. As the key component of hydrogen system, the performance of hydrogen injector significantly influences the characteristic of the mixture before injection into the cylinder. However, current hydrogen injector system using one injector per cylinder is not capable of meeting the flow demand. To investigate the injector's flow characteristics and find a method of improving the injector's flux, a calibration test stand was designed for gas injectors that can exactly calibrate the injector's flow characteristics under injection pressure from 0.2 MPa to 0.45 MPa and injection duration from 1 ms to 10 ms. The minimum injection duration that enables the injector to work steadily was found to increase from 1.8 ms to 2.1 ms, which must be considered in idling speed. In addition, a hydrogen injector model was established using a one-dimensional simulation software. The effect of the structure parameters of the hydrogen injector on the flow characteristics was studied after verification and validation of the model with test data. By comparing the test and the calculation results, the flow area between the armature and the seal was established to have the largest effect on the injector's flow characteristics, and larger flux can be achieved by optimizing the related parameters of the injector. Therefore, the current paper can provide guidance to the technological research on hydrogen injectors in hydrogen internal combustion engine. Copyright (c) 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.