As a kind of band-rejected loss filter, long-period fibre gratings have wide applications in the field of fibre communication and fibre sensing. Combined with the transmission characteristics of long-period fibre gratings, the transmission spectrums of various long-period moiré gratings were simulated by the method of transfer Matrix. The results of analysis indicate that the moiré gratings technology can be well applied in fabricating the high-performance phase-shifted and apodised long-period fibre gratings.