The invention relates to a method for quickly measuring branch angles and joint lengths of crops without losses. The method comprises the following steps that firstly, a picture is taken and is renamed; secondly, the branch angles and the joint length of a stem of the picture are calculated through software, wherein a file of a folder is opened, other files are listed in a table, ranking can be carried out when a table header is clicked, the picture is opened by clicking a line, angles to be calculated are selected, the needed position of a branch is clicked three times, the angles can be obtained, a number is dragged to any position, and after a next picture is clicked, and the result is automatically stored in the Excel table opened at present; the lengths to be calculated are selected, a black strip with the known length is clicked two times, the length of the black strip is calculated, the proportion of the length of the black strip to the actual length is obtained, the position between joints with the distance needing to be calculated is clicked two times, the distance between the joints is worked out, and the actual length of the part between the joints is worked out according to the proportion. By means of the software and the picture taken in a field, lossless measuring can be achieved on the crops in the breeding process for crop breeding people.