ContourPlot3D[
36 Cos[kz]^2 -
4 (-6.5` - 1.5` Cos[2 kx] - 8 Cos[kx - ky] - 8 Cos[2 ky] -
8 Cos[kx + ky] + 4 Cos[2 kz]) == 0, {kx, -1, 1}, {ky, -1,
1}, {kz, -1, 1}]

ContourPlot3D[
36 Cos[kz]^2 -
4 (-6.5` - 1.5` Cos[2 kx] - 8 Cos[kx - ky] - 8 Cos[2 ky] -
8 Cos[kx + ky] + 4 Cos[2 kz]), {kx, -1, 1}, {ky, -1, 1}, {kz, -1,
1}]

谢谢，但是我只需要画恒等于零的那个面

或者说我是要找恒等于零的那些点

ContourPlot3D不适用于画点
{kx, ky, kz} /.
Solve[36 Cos[kz]^2 -
4 (-6.5` - 1.5` Cos[2 kx] - 8 Cos[kx - ky] - 8 Cos[2 ky] -
8 Cos[kx + ky] + 4 Cos[2 kz]) == 0 && -3 <= {kx, ky, kz} <=
3 // Rationalize, {kx, ky, kz},
Method -> Reduce] // ListPointPlot3D