Try using -gravity North
(this will move your text to the top of the image) and then adding an offset (-annotate +0+100
) to move down your text:
convert temp.jpg -gravity North -pointsize 30 -annotate +0+100 'Love you mom' temp1.jpg
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…