An image playing system, comprising a projection device, the projection device comprising a storage circuit, a processor, and a projection module, wherein: the storage circuit is configured to store a playing content comprising at least one multimedia content, a play time length and a play order corresponding to each of the at least one multimedia content, the processor is coupled to the storage circuit and is configured to obtain the playing content from the storage circuit in response to receiving a power signal, and the projection module is coupled to the processor and controlled by the processor to sequentially project the at least one multimedia content according to the play time length and the play order corresponding to each of the at least one multimedia content; characterized in that, the image playing system further comprising: a smart device connected to the projection device through a connection interface, wherein the smart device is configured to transmit the playing content to the projection device through the connection interface; wherein the smart device is configured to plan the at least one multimedia content, the corresponding play time length and the play order to generate the playing content; and wherein the smart device is further configured to: provide a play process editing interface, wherein the play process editing interface comprises a multimedia content type field and a process edit field, wherein the multimedia content type field comprises at least one multimedia object type (410a, 410b, 410c); add a first multimedia object corresponding to a first multimedia object type and a first play time setting value corresponding to the first multimedia object in the process edit field when the first multimedia object type in the at least one multimedia object type (410a, 410b, 410c) is selected; obtain a first multimedia content corresponding to the first multimedia object and set a first play time length corresponding to the first multimedia content according to the first play time setting value; and output the first multimedia content and the corresponding first play time length as the playing content when an edit completion command is detected. the storage circuit is configured to store a playing content comprising at least one multimedia content, a play time length and a play order corresponding to each of the at least one multimedia content, the processor is coupled to the storage circuit and is configured to obtain the playing content from the storage circuit in response to receiving a power signal, and the projection module is coupled to the processor and controlled by the processor to sequentially project the at least one multimedia content according to the play time length and the play order corresponding to each of the at least one multimedia content; a smart device connected to the projection device through a connection interface, wherein the smart device is configured to transmit the playing content to the projection device through the connection interface; wherein the smart device is configured to plan the at least one multimedia content, the corresponding play time length and the play order to generate the playing content; and wherein the smart device is further configured to: provide a play process editing interface, wherein the play process editing interface comprises a multimedia content type field and a process edit field, wherein the multimedia content type field comprises at least one multimedia object type (410a, 410b, 410c); add a first multimedia object corresponding to a first multimedia object type and a first play time setting value corresponding to the first multimedia object in the process edit field when the first multimedia object type in the at least one multimedia object type (410a, 410b, 410c) is selected; obtain a first multimedia content corresponding to the first multimedia object and set a first play time length corresponding to the first multimedia content according to the first play time setting value; and output the first multimedia content and the corresponding first play time length as the playing content when an edit completion command is detected. provide a play process editing interface, wherein the play process editing interface comprises a multimedia content type field and a process edit field, wherein the multimedia content type field comprises at least one multimedia object type (410a, 410b, 410c); add a first multimedia object corresponding to a first multimedia object type and a first play time setting value corresponding to the first multimedia object in the process edit field when the first multimedia object type in the at least one multimedia object type (410a, 410b, 410c) is selected; obtain a first multimedia content corresponding to the first multimedia object and set a first play time length corresponding to the first multimedia content according to the first play time setting value; and output the first multimedia content and the corresponding first play time length as the playing content when an edit completion command is detected.