KDE对多点触控屏的支持没有windows那么优秀，只能使用类似鼠标的单击操作。
下面是直接使用xinput禁用。
thinkt@linux-pw37:/usr/share/X11/xorg.conf.d> xinput
? Virtual core pointer                          id=2    [master pointer  (3)]
?   ? Virtual core XTEST pointer                id=4    [slave  pointer  (2)]
?   ? Logitech Optical USB Mouse                id=10   [slave  pointer  (2)]
?   ? TPPS/2 IBM TrackPoint                     id=14   [slave  pointer  (2)]
?   ? Melfas LGD AIT Touch Controller           id=9    [slave  pointer  (2)]
?   ? SynPS/2 Synaptics TouchPad                id=13   [slave  pointer  (2)]
? Virtual core keyboard                         id=3    [master keyboard (2)]
    ? Virtual core XTEST keyboard               id=5    [slave  keyboard (3)]
    ? Power Button                              id=6    [slave  keyboard (3)]
    ? Video Bus                                 id=7    [slave  keyboard (3)]
    ? Sleep Button                              id=8    [slave  keyboard (3)]
    ? Integrated Camera                         id=11   [slave  keyboard (3)]
    ? AT Translated Set 2 keyboard              id=12   [slave  keyboard (3)]
    ? ThinkPad Extra Buttons                    id=15   [slave  keyboard (3)]
thinkt@linux-pw37:/usr/share/X11/xorg.conf.d> xinput disable 9
也可以修改/usr/share/X11/xorg.conf.d/10-evdev.conf，添加Option "Ignore" "on"

Section "InputClass"
        Identifier "evdev touchscreen catchall"
        MatchIsTouchscreen "on"
        MatchDevicePath "/dev/input/event*"
        Driver "evdev"
        Option "Ignore" "on"
EndSection