A pet stroller with an adjustable supporting frame and canopy structure, comprising: a pet stroller body comprising a frame shaped chassis rack which comprises a rear frame arranged on a back side thereof, a folding brace respectively diagonally arranged on two sides of said frame shaped chassis rack and said rear frame, a stroller grip extendedly arranged on a top of said rear frame, a base plate arranged on said frame shaped chassis rack, two steering wheels respectively arranged on two sides of a front end of said frame shaped chassis rack, and two wheels respectively arranged on two sides of a back end of said frame shaped chassis rack; characterized in that the pet stroller comprises an adjustable supporting frame comprising two rotation shaft boxes respectively arranged on inner sides of said folding brace of two sides of said pet stroller body, wherein each of said rotation shaft boxes is connected with said frame shaped chassis rack and said rear frame respectively through first and second props, wherein each of said rotation shaft boxes comprises a canopy strut extended diagonally upwards from a front end thereof and a front window strut extended forward parallelly from said front end thereof, wherein said front window strut has two sliding sleeves respectively arranged on two sides thereof, wherein each of said sliding sleeves is connected to said frame shaped chassis rack through a third prop; and an adjustable canopy covering on an external side of said pet stroller body and corresponding to said adjustable supporting frame, wherein said adjustable canopy is able to be transformed among a covering mode, a front opening mode and a full-opening mode through adjusting positions of said canopy strut and said front window strut. a pet stroller body comprising a frame shaped chassis rack which comprises a rear frame arranged on a back side thereof, a folding brace respectively diagonally arranged on two sides of said frame shaped chassis rack and said rear frame, a stroller grip extendedly arranged on a top of said rear frame, a base plate arranged on said frame shaped chassis rack, two steering wheels respectively arranged on two sides of a front end of said frame shaped chassis rack, and two wheels respectively arranged on two sides of a back end of said frame shaped chassis rack; characterized in that the pet stroller comprises an adjustable supporting frame comprising two rotation shaft boxes respectively arranged on inner sides of said folding brace of two sides of said pet stroller body, wherein each of said rotation shaft boxes is connected with said frame shaped chassis rack and said rear frame respectively through first and second props, wherein each of said rotation shaft boxes comprises a canopy strut extended diagonally upwards from a front end thereof and a front window strut extended forward parallelly from said front end thereof, wherein said front window strut has two sliding sleeves respectively arranged on two sides thereof, wherein each of said sliding sleeves is connected to said frame shaped chassis rack through a third prop; and an adjustable canopy covering on an external side of said pet stroller body and corresponding to said adjustable supporting frame, wherein said adjustable canopy is able to be transformed among a covering mode, a front opening mode and a full-opening mode through adjusting positions of said canopy strut and said front window strut.