Abstract: A printer and a printing method therefor is disclosed. The printing method includes: S1: editing a print template at a printer, the edited print template including a custom field and a variable field, and printing the custom field before the variable field; S2: obtaining weighing data at a weighing instrument; S3: obtaining weighing data that matches the variable field, inserting the matched weighing data in a position of the corresponding variable field, and printing the weighing data after the weighing data is completely matched; determining whether the weighing data at the instrument is completely sent and/or completely obtained by the printer, and if the weighing data is not completely sent and/or obtained, returning to step S2, or if the weighing data is completely sent and/or obtained, performing step S5; and S5: if there is still a custom field not printed in the print template, printing the custom field not printed.