$ cat /etc/samba/smb.conf
[global]
workgroup = WORKGROUP
security = user
encrypt passwords = yes
passdb backend = smbpasswd
map to guest = Bad User
usershare allow guests = Yes
ntlm auth = yes
[yuan]
comment = yuan home directory
path = /home/yuan
read only = no
# guest ok = yes
browseable = yes
writable = Yes
valid users = yuan
加上 ntlm auth = yes 就ok了。
https://superuser.com/questions/1125438/windows-10-password-error-with-samba-share