To improve the detection efficacy of banana streak virus co-infections, this study established multiplex immunocapture PCR for detection of co-infection of banana streak OL virus (BSOLV), banana streak GF virus (BSGFV) and banana streak IM virus (BSIMV). The specific primers were designed to identify the conserved sequences of the coat protein (CP) gene of BSOLV and BSGFV, and the RNase H gene of BSIMV. The BSVs were captured by BSV polyclonal antiserum as templates for a multiplex immunocapture PCR. After optimizing the reaction conditions including primer concentration and annealing temperature, a multiplex immunocapture PCR method was developed for simultaneous detection of BSOLV, BSGFV, and BSIMV. The results indicated that the multiplex immunocapture PCR technique could identify BSOLV, BSGFV, and BSIMV at each primer concentration of 0.5 μM from 1 mg/mL of banana sap at an annealing temperature of 62.9°C. The multiplex immunocapture PCR method was not able to detect the similar symptoms of banana caused by cucumber mosaic virus (CMV), and exhibited no cross-reactivity with CMV, indicating that the established multiplex immunocapture PCR method had good specificity. These results demonstrate that the multiplex immunocapture PCR method had high sensitivity and specificity for BSV, enabling its application in detecting the three BSVs in banana seedlings, as well as banana samples in the field.