Thanks for your reply. I get addtional head points by following the tutorial https://neuroimage.usc.edu/brainstorm/Tutorials/ChannelFile to get the head points. Actually I want to know, when the three fiducials point can not consist with the head model, but the addtional head points can, if I ignore the fiducial points , and use the addtional points to achieve registration for MEG helmet and MRI head model, can I get the right source estimation?