Based on the gas cloud deflagration experimental platform, the propane-air premixed gas blasting experiments inside curved pipelines of different length are carried out. The curved pipeline length effect on the combustible gas explosion in pipeline and the explosion shock wave effect on thin-walled pipeline loading are investigated. Photoelectric, pressure and strain sensors are used to evaluate the explosion parameters within the pipeline and the stress-strain relation of the thin-walled pipeline, respectively. The results indicate that a longer pipeline corresponds to the higher wall overpressure and the bigger maximum strain of the pipeline wall. The pressure-time curve is in good agreement with the thin-walled pipeline strain-time history curve. The curved shape of the pipeline accelerates the flame propagation to a certain extent, and the flame propagation rate decreases to the minimum value at the 90 degree inflexion. The pipeline length has global effects on the flame deflagration within the pipeline. A longer pipeline results in higher pressure and flame speed. The maximum explosion pressure appears at the end of the pipeline, and the loading of the shock wave to the pipeline wall belongs to the dynamic loading.