We have proposed a novel method for designing the second_order planar gradiomete rs and even high_order gradiometers.The gradiometer consists of two parts,one is the superconducting quantum interference device(SQUID),the other is the pickup loop which is directly coupled with the SQUID.The pickup loop consists of two p arallel_connected loops,each loop consists of several opening loops which are co nnected with minimal channels between them.By adjusting the site,size and shape of these opening loops,we can realize that the current in the common line betwee n the two loops is proportioned by the high_order gradient of the magnetic field .Because the line is coupled with SQUID,so we can measure the high_order gradien t of the magnetic field.We have got the relations between the site and the size of loops by calculation, and prove it can work.For high_order gradiometers,the baseline is important.Our design can use flip_chip configration to lengthen the baseline.Another method to get longer baseline is to design two_dimensional gradiometers which are easy to design using our method.