Abstract: The glass fiber yarn is damaged easily during knitting process and difficult to be knitted into fabric. The knitting experiments are carried out with two specific glass fiber yarns knitted on different machine type. The influencing factors such as knitting elements, let-off device, take-up and batching mechanism, yarn twist, direction of twist, Glass fiber soakage agent are discussed. The bad side of fabric which is caused by yarn twist and direction of twist is analyzed. The key warp knitting technology of glass fiber is concluded. It’s proved that textile glass fiber yarn can be knitted successfully on tricot warp knitting machine with compound needle and positive let-off Mechanism.