The invention relates to a pharmaceutical composition comprising Morinda officinalis oligosaccharide extract and a non-sugar antidepressant as active components. It is characterized in that the total content of inulin-type oligosaccharides in the extract of Morinda officinalis oligosaccharides is 50-70%, and the content of inulin-type pentameric oligosaccharides is 5-15%; non-sugar antidepressants include Monoamine oxidase inhibitor antidepressant drugs such as moclobemide, norepinephrine reuptake inhibitor antidepressant drugs such as imipramine, amitriptyline, maprotiline, doxepin, clomipa antidepressants such as fluoxetine, paroxetine, sertraline or citalopram, etc., or dual norepinephrine / selective serotonin Non-carbohydrate antidepressants of the reuptake inhibitor class, such as mirtazapine, duloxetine, venlafaxine, or desmethylvenlafaxine. The present invention also relates to the use of the pharmaceutical composition of Morinda officinalis oligosaccharide extract and a non-saccharide antidepressant drug as active ingredients in treating neuropsychiatric diseases such as depression, anxiety, and neurogenic pain.