Abstract: ZTL/1000 continuous flow roadway outburst forecast device is a "linearly predict" device for coal and gas outburst risk, which can truly reflect the outburst ahead of coal roadway. In the forecast system of outburst of coal laneway with method of continuous flow, drilling bit position is determined by determining the drilling distance of the drilling outside drill-pipe in the process of continuous flow method roadway outburst prediction. Original measuring device uses cable-displacement sensor to determine drilling distance, but it is easy to block line, forceful rebound and operation inconvenience, which leads to inaccurate position of drill bit in the drilling process and affect prediction effect. To overcome this shortcoming, this paper makes re-experimental study for the drill location determination technology.