He, Y. JACoW Geneva, Switzerland Since 2011, the key technologies for superconducting proton linac were developed in CAS for Accelerator Driven System. The sc linac of 10 MeV base on spoke resonators (Spoke), named injector I, was built in IHEP. The other one base on half-wave resonators (HWR), named injector II, was built in IMP. Both injectors were commissioned successfully with more than 1 mA CW beam. The front-end demo linac for ADS is based on injector II with succeeding by one taper-type HWR cryomodule and one Spoke cryomodule. It can accelerate 10 mA beam to energy of 25 MeV. The last two cryomodules of the demo linac started tunnel installation since January and cooling down in May. The first beam was on May 27th, and 12 mA (@ 26 MeV) pulse beam and 170 us (@ 25 MeV) CW beam were demonstrated on July 6th. The background of the project will be introduced. The lessons and experiences of CW SRF and mA beam commissioning on injector II and the 25 MeV demo linac will be presented.