Abstract: It is very difficult to transmit femtosecond pulses with high energy density in traditional optical fiber. So, a hollow single-mode Bragg fiber was designed. First, the cladding of hollow Bragg fiber was prepared based on one-dimensional photonic crystal's bandgap characteristics. Then, the fiber structure parameters and transmission properties were analyzed by using the optical software FDTD Solutions. And then, the structure parameters were optimized to control dispersion curves through bringing in defect layer in cladding layer. It can be seen by full bandwidth scanning that the fundamental mode bandwidth achieve around 100 nm which can transmit 100 fs optical pulses.