We investigated the block shear performance of 16 steel angle specimens connected by double-line bolts. Among these specimens, 10 were made of S690 high-strength steel and 6 were made of normal-strength steel. The angle specimens were fabricated using two hot-rolled steel plates through groove welding. Two angle sections, i.e., 125 × 65 × 6 and 125 × 85 × 6 mm (long leg length × short leg length × thickness), were considered in the test. All angles were connected to the long leg. Apart from steel grade, the test parameters included bolt rows, parallel pitch, transverse pitch, edge distance, and unconnected leg length. Typical block shear of specimens were observed, and different fracture patterns were characterised. The test results confirmed that the block shear strength of the tension angles could be improved by increasing the tension plane area with the increase of the transverse pitch and edge distance and increasing the shear plane area with the increase of the bolt row number and parallel pitch. However, the test results showed that the block shear strength of the angles was not affected by the length of the unconnected leg. Subsequently, numerical models were built to further investigate the block shear behaviour of the double-line bolted angles, and the analysis parameters were the end distance, unconnected leg length, and connected leg length. According to the experimental and numerical results, the accuracy and adequacy of design specifications in the United States, Europe, Canada, and Japan and design equations documented in the literature for evaluating the block shear performance of double-line bolted steel angles were evaluated.