When large crosssection tunnels are excavated in waterrich fine silty sand ground, advance horizontal jet grouting pipes are needed to reinforce the tunnel face so as to ensure safe excavation. Therefore, it is very important to ensure the quality of the horizontal jet grouting piles. The quality of 5 horizontal jet grouting piles installed in the top heading of a tunnel is detected by low strain reflection wave method. The detection results are compared with the actual quality of the piles exposed, which demonstrates that the low strain reflection wave method adopted is a fast, reliable and nondestructive qualitydetection mehtod.