Thank you for your reply!My dataset is about DNA sequence,such as a dog’s sequence maybe like this,[ATCGATCG],it contain four alphabet:ATCG,the order of the DNA sequence contain some information that we can conclude which species it is.So,it’s difficult to do augmentation,not as easy as images,if I just have one dog,which means I just have one DNA sequence.Thus,I split the datasets in random.If you have  some good advice,please tell me,thank you,sir.