原因是ARM开发板中环境变量屏幕分辨率和DPI参数不对。终端下vi /etc/profile打开后作如下修改：
# /etc/profile
PATH=$PATH:/bin:/sbin:/usr/bin:/usr/sbin
LD_LIBRARY_PATH=/lib:usr/lib:/opt/qt-4.8/lib $LD_LIBRARY_PATH
export LD_LIBRARY_PATH
export HOME=/root
export QTDIR=/opt/qt-4.8
export QPEDIR=/opt/qt-4.8
export QWS_DISPLAY="LinuxFB:/dev/fb0" //此处应该改为export QWS_SIZE="800X600"
export QWS_DISPLAY="LinuxFB:mmWidth130:mmHeight100:0" //此处应该改为export QWS_DISPLAY="LinuxFB:mmWidth243:0"
export QWS_KEYBOARD="TTY:/dev/tty1"
export TSLIB_TSDEVICE=/dev/input/event0
export TSLIB_CALIBFILE=/etc/pointercal
export TSLIB_CONFFILE=/etc/ts.conf
export TSLIB_PLUGINDIR=/lib/ts
export QWS_MOUSE_PROTO="tslib:/dev/input/event0 Intellimouse:/dev/mouse1"
export QT_PLUGIN_PATH=$QTDIR/plugins/
export QT_QWS_FONTDIR=$QTDIR/lib/fonts/
export PATH=$QPEDIR/bin:$PATH
export LD_LIBRARY_PATH=$QTDIR/lib:$QPEDIR/plugins/imageformats:$LD_LIBRARY_PATH
USER="'id -un'"
LOGNAME=$USER
PS1='[\u@\h \w]\$'
HOSTNAME='/bin/hostname'
export USER LOGNAME PS1