The invention discloses an alarm information visualization method used for an electrical network trend graph and a system. The method comprises: reading alarm information after receiving an alarm event body by a human machine; quickly positioning the alarm-happening position in a bull's eye flashing mode by a human machine system; cutting out interval diagrams connected by faulted members according to a power grind topology relation, performing data correlation and topology coloring on interval diagrams, splicing the faulted member and the interval diagrams which are cut out according to the power grid topology relation to automatically generate a fault detailed information diagram, making the background color of the original trend diagram dark and highlighting the fault detailed information diagram. When the power grid has abnormal information, the abnormity of the power grid can be quickly positioned through the invention, the local detailed diagram can be automatically generated through cutting and splicing, the common display of the trend diagram and the detailed diagram can be achieved, and the abnormality of the power grid system can be seen through quickly by the scheduling personnel at first time.