2.步骤

（０）查看外接显示器名称

yuan@yuan:~/桌面$ xrandr
Screen 0: minimum 320 x 200, current 3286 x 1080, maximum 32767 x 32767
LVDS1 connected primary 1366x768+0+0 (normal left inverted right x axis y axis) 309mm x 173mm
   1366x768       60.0*+
   1360x768       59.8     60.0  
   1024x768       60.0  
   800x600        60.3     56.2  
   640x480        59.9  
VGA1 connected 1920x1080+1366+0 (normal left inverted right x axis y axis) 0mm x 0mm
   1920x1080      60.0  
   1024x768       60.0  
   800x600        60.3     56.2  
   848x480        60.0  
   640x480        59.9  
   1920x1080_60.00   60.0* 
HDMI1 disconnected (normal left inverted right x axis y axis)
DP1 disconnected (normal left inverted right x axis y axis)
VIRTUAL1 disconnected (normal left inverted right x axis y axis)

（１）查看1920x1080分辨率模式

yuan@yuan:~/桌面$ cvt 1920 1080
# 1920x1080 59.96 Hz (CVT 2.07M9) hsync: 67.16 kHz; pclk: 173.00 MHz
Modeline "1920x1080_60.00"  173.00  1920 2048 2248 2576  1080 1083 1088 1120 -hsync +vsync

（２）添加newmode

sudo xrandr --newmode "1920x1080_60.00" 173.00 1920 2048 2248 2576 1080 1083 1088 1120 -hsync +vsync

（３）添加1920x1080模式

yuan@yuan:~/桌面$ sudo xrandr --addmode VGA1 "1920x1080_60.00"

（４）执行输出

yuan@yuan:~/桌面$ xrandr --output VGA1 --mode "1920x1080_60.00" --rate 60