Finally I found the leakage point of hydraulic main cylinder.
It was not because of Tube O-ring but cylinder inside packing.
Anyone have good idea to fix it without rebuilt?
My idea is that put on thin glue or silicon at leakage point and pulling the piston rod to invade it inside.

 

I am fairly sure it has been attempted to "fix" leaking hydraulic cylinders many times and without very expensive equipment it just is not possible. I remember a few years ago there was a guy who said he had done a successful DIY to come back two weeks later and ask for the address of the "guy" who refurbishes leaking top cylinders. My guess is, you won't have success with simply putting some silicone there and I'm also guessing you might do more damage than good.
Sending them in to one of the recommended vendors might be your best bet.

 

I agree with nickwe21. The amount of pressure in the system will just blow that repair out.