A construction assisting system including a controller that performs construction assistance processing of assisting in construction performed by a work machine on a basis of positional relation between a worker and the work machine, and a worker position information obtaining device that obtains position information of the worker; characterized in that: the construction assisting system is further comprising: an approach intention detecting device that notifies the worker of an inquiry about an intention to approach the work machine when the worker intrudes into a notification region set further outward of a movable region set as a range reachable by a structure of the work machine, and detects the intention of the worker to approach the work machine on a basis of a response to the inquiry from the worker; an approach intention presenting device that presents a detection result of the approach intention detecting device to an operator of the work machine; and an approach confirmation obtaining device that obtains a confirmation state of the operator of the work machine for contents presented by the approach intention presenting device, the controller performing safety operation as the construction assistance processing when determining that the worker has intruded into the movable region on a basis of the position information obtained by the worker position information obtaining device when the confirmation state obtained by the approach confirmation obtaining device is a state in which the operator of the work machine denies an approach of the worker or when the operator of the work machine does not confirm the intention of the worker to approach. a worker position information obtaining device that obtains position information of the worker; characterized in that: the construction assisting system is further comprising: an approach intention detecting device that notifies the worker of an inquiry about an intention to approach the work machine when the worker intrudes into a notification region set further outward of a movable region set as a range reachable by a structure of the work machine, and detects the intention of the worker to approach the work machine on a basis of a response to the inquiry from the worker; an approach intention presenting device that presents a detection result of the approach intention detecting device to an operator of the work machine; and an approach confirmation obtaining device that obtains a confirmation state of the operator of the work machine for contents presented by the approach intention presenting device, the controller performing safety operation as the construction assistance processing when determining that the worker has intruded into the movable region on a basis of the position information obtained by the worker position information obtaining device when the confirmation state obtained by the approach confirmation obtaining device is a state in which the operator of the work machine denies an approach of the worker or when the operator of the work machine does not confirm the intention of the worker to approach. an approach intention detecting device that notifies the worker of an inquiry about an intention to approach the work machine when the worker intrudes into a notification region set further outward of a movable region set as a range reachable by a structure of the work machine, and detects the intention of the worker to approach the work machine on a basis of a response to the inquiry from the worker; an approach intention presenting device that presents a detection result of the approach intention detecting device to an operator of the work machine; and an approach confirmation obtaining device that obtains a confirmation state of the operator of the work machine for contents presented by the approach intention presenting device, the controller performing safety operation as the construction assistance processing when determining that the worker has intruded into the movable region on a basis of the position information obtained by the worker position information obtaining device when the confirmation state obtained by the approach confirmation obtaining device is a state in which the operator of the work machine denies an approach of the worker or when the operator of the work machine does not confirm the intention of the worker to approach.