Time-resolved measurement of laser-induced breakdown spectrum (LIBS) is valuable in many applications. However, it is of high technical challenges. Thus, a new LIBS method based on multiple channel fiber bundle is developed. In this method, a fiber bundle consisting of many fibers with different lengths was first used to delay the signal of LIBS. Then, the spectra from different channels were recorded by an intensified charge-coupled device (ICCD) in different areas. For demonstration, a fiber bundle with 19 channels was constructed. The length of the fiber was in an arrangement of arithmetic sequence with a difference of 10m, corresponding to an interval time of 50 ns. The full recording length was 0.9 μs. The system was used to measure the breakdown spectrum of Si. The results showed multiple spectrum lines at 390.52 nm (Si Ⅰ),385.51 nm (Si Ⅱ),and 413.12 nm(Si Ⅱ) at 19 moments of 898 ns, which clearly exhibited the dynamic development of the breakdown spectrum. This new method can acquire the spectra at different moments in a single measurement. Therefore, it has a very high measurement efficiency. In particular, for experiments with expensive costsor low operation frequencies, this method could reduce the cost, efficiently increasing the ability of time-resolved spectrum measurement.