Abstract: In order to study the fatigue crack growth (FCG) behavior of Q690D high-strength steel (HSS) butt weld (BW), the FCG tests of Q690D HSS BW were carried out. The FCG rates (FCGR) and threshold values of BW are analyzed for different stress ratios and plate thicknesses. A modified PARIS formula is fitted. An expression for the threshold values that integrates the effect of stress ratio is established. The calculation formula of crack closure parameter is derived based on the energy principle in the FCG process. The results show that the Q690D HSS BW has good FCG resistance. The FCGR is 0.33~0.59 times of the recommended value of BS 7910 specification. The FCGR of BW increases with the increase of stress ratio and plate thickness. When the stress ratio R increases from 0.1 to 0.5, the FCGR increases by 87.26%. When the plate thickness increases from 10 mm to 16 mm, the FCGR increases by 23.01%. The FCG threshold value of HSS BW is less than the recommended value of BS7910 specification. When the stress ratio R is 0.1, the test results are 2.215 times of code-specified values. The FCG threshold value decreases linearly with the increase of stress ratio.