Which distro do you have on emmc?
All new images are using mainline uboot and you will need to get rid of bsp uboot in emmc or triple press function button to skip emmc boot.
Thank you，but I have set the autologin because my vim3 is inside in another device ，need I press that buttom every time I launch manjaro？
It depends what you have on emmc.
If you flash Manjaro on emmc then you don’t need to press any button.
I see，thank you very much ，I give a try to burn image on emmc next time